Harnessing Nature's ingenuity to engineer butterfly-wing-inspired photoactive nanofiber patches for advanced postoperative tumor treatment.

Postoperative tumor treatment necessitates a delicate balance between eliminating residual tumor cells and promoting surgical wound healing. Addressing this challenge, we harness the innovation and elegance of nature's ingenuity to develop a butterfly-wing-inspired photoactive nanofiber patch (WingPatch), aimed at advancing postoperative care. WingPatch is fabricated using a sophisticated combination of electrostatic spinning and spraying techniques, incorporating black rice powder (BRP) and konjac glucomannan (KGM) into a corn-derived polylactic acid (PLA) nanofiber matrix. This fabrication process yields a paclitaxel-infused porous nanofiber architecture that mirrors the delicate patterns of butterfly wings. Meanwhile, all-natural composites have been selected for their strategic roles in postoperative recovery. BRP offers the dual benefits of photothermal therapy and antibacterial properties, while KGM enhances both antibacterial effectiveness and tissue regeneration. Responsive to near-infrared light, WingPatch ensures robust tissue adhesion and initiates combined photothermal and chemotherapeutic actions to effectively destroy residual tumor cells. Crucially, it simultaneously prevents infections and promotes wound healing throughout the treatment process. Its effectiveness has been confirmed by animal studies, and WingPatch significantly improves treatment outcomes in both breast and liver tumor models. Thus, WingPatch exemplifies our dedication to leveraging natural world's intricate patterns and inventiveness to propel postoperative care forward.

Bioinspired Hierarchical T Structures for Tunable Wettability and Droplet Manipulation by Facile and Scalable Nanoimprinting.

Developing surfaces that effectively repel low-surface-tension liquids with tunable adhesive properties remains a pivotal challenge. Micronano hierarchical re-entrant structures emerge as a promising solution, offering a robust structural defense against liquid penetration, minimizing area fraction, and creating narrow gaps that generate substantial upward Laplace pressure. However, the absence of an efficient, scalable, and tunable construction method has impeded their widespread applications. Here, drawing inspiration from springtail epidermal structures, octopus suckers, and rose petals, we present a scalable manufacturing strategy for artificial micronano hierarchical T-shaped structures. This strategy employs double-transfer UV-curing nanoimprint lithography to form nanostructures on microstructured surfaces, offering high structural tunability. This approach enables precise control over topography, feature size, and arrangement of nano- and microscale sections, resulting in superamphiphobic surfaces that exhibit high contact angles (>150°) and tunable adhesive forces for low-surface-energy liquids. These surfaces can be applied to droplet-based microreactors, programmable droplet-transfer systems, and self-cleaning surfaces suitable for various liquids, particularly those with low surface tension. Remarkably, we have also succeeded in fabricating the hierarchical structures on flexible and transparent substrates. We demonstrate the advantages of this strategy in the fabrication of hierarchical micronanostructures, opening up a wide range of potential applications.

A Rapid Fabrication Method of Large-Area MLAs with Variable Curvature for Retroreflectors Based on Thermal Reflow.

Retroreflectors are an important optical component, but current retroreflector structures and manufacturing processes are relatively complex. This paper proposes a rapid, low-cost, large-area method for fabricating retroreflectors based on microlens arrays. Tunable microlens arrays with adjustable curvature, fill factor, and sizes were prepared using photolithography and thermal reflow techniques. Subsequently, a two-step nanoimprinting process was used to create a flexible reverse mold and transfer the structure onto the desired substrate. The microlens arrays, with a diameter of 30 µm, a period of 33 µm, a curvature radius ranging from 15.5 to 18.8 µm, and a fill factor ranging from 75.1% to 88.8%, were fabricated this way. In addition, the method also fabricated microlens arrays with diameters ranging from 10 to 80 µm. Retroreflectors were made by sputtering a layer of silver on the MLAs as a reflecting layer, and tests showed that the microlens-based retroreflector exhibited superior retroreflective performance with a wide-angle response of ±75°. Microlens-based retroreflectors have the advantages of simple operation and controllable profiles. The fabrication method in this paper is suitable for large-scale production, providing a new approach to retroreflector design.

Room-Temperature Growth of Square-Millimeter Single-Crystalline Two-Dimensional Metal Halides on Silicon.

Silicon is the cornerstone of electronics and photonics. In this context, almost all integrated devices derived from two-dimensional (2D) materials stay rooted in silicon technology. However, as the growth substrate, silicon has long been thought to be a hindrance for growing 2D materials through bottom-up methods that require high growth temperatures, and thus, indirect routes are usually considered instead. Although promising growth of large-area 2D materials on silicon has been demonstrated, the direct growth of single-crystalline materials using low-thermal-budget synthesis methods remains challenging. Here, we report the room-temperature growth of millimeter-scale single-crystal 2D metal halides on silicon substrates with a hydroxyl-terminated surface. Theoretical calculations reveal that the activation energy for surface diffusion can be reduced by an order of magnitude by terminating the surface with hydroxyl groups, from which on-silicon growth is greatly facilitated at room temperature and enables a 4-order-of-magnitude increase in area. The high quality and uniformity of the resulting single crystals are further evidenced. The optoelectronic devices employing the as-grown materials show an ultralow dark current of 10-13 A and a high detectivity of 1013 Jones, thereby corroborating a weak-light detection ability. These results would point to a rich space of surface modulation that can be used to surmount current limitations and demonstrate a promising strategy for growing 2D materials directly on silicon at room temperature to produce large single crystals.

Bioinspired Polymer Films with Surface Ordered Pyramid Arrays and 3D Hierarchical Pores for Enhanced Passive Radiative Cooling.

Passive radiative cooling (PRC) has been acknowledged to be an environmentally friendly cooling technique, and especially artificial photonic materials with manipulating light-matter interaction ability are more favorable for PRC. However, scalable production of radiative cooling materials with advanced biologically inspired structures, fascinating properties, and high throughput is still challenging. Herein, we reported a bioinspired design combining surface ordered pyramid arrays and internal three-dimensional hierarchical pores for highly efficient PRC based on mimicking natural photonic structures of the white beetle Cyphochilus' wings. The biological photonic film consisting of surface ordered pyramid arrays with a bottom side length of 4 µm together with amounts of internal nano- and micropores was fabricated by using scalable phase separation and a quick hot-pressing process. Optimization of pore structures and surface-enhanced photonic arrays enables the bioinspired film to possess an average solar reflectance of ∼98% and a high infrared emissivity of ∼96%. A temperature drop of ∼8.8 °C below the ambient temperature is recorded in the daytime. Besides the notable PRC capability, the bioinspired film exhibits excellent flexibility, strong mechanical strength, and hydrophobicity; therefore, it can be applied in many complex outdoor scenarios. This work provides a highly efficient and mold replication-like route to develop highly efficient passive cooling devices.

Open-Microcolumn Array: A Novel Approach for Enhanced Electrocatalytic Bubble Desorption in Microreactors.

High-efficiency electrocatalytic water splitting requires high intrinsic activity of catalysts and even more importantly favorable mass transfer. However, gas bubbles adhering to the surface of catalysts limit the re-expose of catalytic active sites to the electrolyte and reduce the catalytic activities. The efficient desorption of bubbles can be facilitated by a hierarchical multiscale structure of the electrode surface. Herein, we report an opened periodic three-dimensional electrode composed of iron (Fe)-cobalt (Co)-nickel (Ni) (oxy)hydroxide nanorods (NRs) grown in situ on a high aspect ratio nickel microcolumn array (NCA) for electrocatalytic water splitting. Compared with the flat nickel plate, the NCA not only increases the surface area for catalyst loading but also improves the wettability of the electrolyte on the electrode surface, exhibiting superhydrophilicity/superaerophobicity (the electrolyte and the bubble contact angles were about ∼0 and 163°, respectively), which accelerates the bubble evolution and desorption process. The X-ray photoelectron spectroscopy indicates that the synergy of Fe-Co-Ni could enhance the ratio of Co3+/Co2+ and Ni3+/Ni2+ and promote the electrocatalytic activity. Benefiting from the microstructure design and synergistic effects, the Co4Fe0.5Ni0.5OOH-NR@NCA electrode achieves a superior OER performance with an overpotential of 199 mV at 10 mA·cm-2.

A Smart "Energy NanoLock" Selectively Blocks Oral Cancer Energy Metabolism through Synergistic Inhibition of Exogenous Nutrient Supply and Endogenous Energy Production.

The major challenge in oral cancer is the lack of state-of-the-art treatment modality that effectively cures cancer while preserving oral functions. Recent insights into tumor metabolic dependency provide a therapeutic opportunity for exploring optimal treatment approaches. Herein, a smart responsive "Energy NanoLock" is developed to improve cancer metabolic intervention by simultaneously inhibiting nutrient supply and energy production. NanoLock is a pomegranate-like nanocomplex of cyclicRGD-modified carboxymethyl chitosan (CyclicRC, pI = 6.7) encapsulating indocyanine green and apoptotic peptides functionalized gold nanoparticles (IK-AuNPs), which together form a dual pH- and photoresponsive therapeutic platform. NanoLock exhibits good stability under physiological conditions, but releases small-size CyclicRC and IK-AuNPs in response to the tumor acidic microenvironment, leading to deep tumor penetration. CyclicRC targets integrins to inhibit tumor angiogenesis, and consequently blocks tumor nutrient supply. Meanwhile, IK-AuNPs specifically induce apoptotic peptides and photothermally mediated mitochondrial collapse, and consequently inhibits endogenous energy production, thereby facilitating cell death. Importantly, in both xenograft and orthotopic oral cancer models, NanoLock selectively eliminates tumors with little cross-reactivity with normal tissues, especially oral functions, resulting in prolonged survival of mice. Therefore, NanoLock provides a novel metabolic therapy to exploit synergistic inhibition of exogenous nutrient supply and endogenous energy production, which potentially advances oral cancer treatment.

Tube-Sponge-Inspired Hierarchical Electrocatalysts with Boosted Mass and Electron Transfer for Efficient Oxygen Evolution.

Hindered gas bubble release and limited electron conducting process represent the major bottlenecks for large-scale electrochemical water splitting. Both the desorption of bubbles and continuous electron transport are achievable on the surfaces of biomimetic catalytic materials by designing multiscale structural hierarchy. Inspired by the tubular structures of the deep-sea sponges, an exceptionally active and binder-free porous nickel tube arrays (PNTA) decorated with NiFe-Zn2+ -pore nanosheets (NiFe-PZn ) are fabricated. The PNTA facilitate removal of bubbles and electron transfer in the oxygen evolution reaction by reproducing trunks of the sponges, and simultaneously, the NiFe-PZn increase the number of catalytic active sites by simulating the sponge epidermis. With improved external mass transfer and interior electron transfer, the hierarchical NiFe-PZn @PNTA electrode exhibits superior oxygen evolution reaction performance with an overpotential of 172 mV at 10 mA cm-2 (with a Tafel slope of 50 mV dec-1 ). Furthermore, this electrocatalytic system recorded excellent reaction stability over 360 h with a constant current density of 100 mA cm-2 at the potential of 1.52 V (versus RHE). This work provides a new strategy of designing hierarchical electrocatalysts for highly efficient water splitting.

Orthogonal Chemical Reporter Strategy Enables Sensitive and Specific SERS Detection of Hydrazine Derivatives.

Hydrazine and its derivatives are well-known environmental hazards and biological carcinogens; therefore, there is a great need for a powerful workflow solution for protecting the public from unexpected exposure to toxic contaminants. Recently, functional surface-enhanced Raman scattering (SERS) exhibits enormous benefits in sensing trace biochemical substances due to its fingerprint-like identification of individual molecules, making it an ideal method for detecting and quantifying hydrazine. Herein, for the first time, we integrated the orthogonal chemical reporter strategy with SERS to build an intelligent hydrazine detection platform (orthogonal chemical SERS, ocSERS), in which 4-mercaptobenzaldehyde was incorporated on a nanoimprinted gold nanopillar array, which acted as an orthogonal coupling partner of hydrazine to form Raman active benzaldehyde hydrazone, allowing for sensitively detecting hydrazine with a detection limit of 10-13 M in complex circumstances. Particularly, ocSERS could effectively identify the carcinogen N-nitrosodimethylamine (NDMA) after its reduction to dimethylhydrazine (UDMH), enabling ultrasensitive detection of UDMH (10-13 M). Importantly, ocSERS could not only monitor elevated levels of NDMA in ranitidine due to improper storage but also quantify NDMA in urine and blood after oral administration of NDMA-containing drugs, thereby preventing NDMA overexposure. Therefore, ocSERS represents the first click SERS sensor and may open up a new analytical field.

Bioinspired All-in-One Three-Dimensional Dynamic CellMatrix Improves the Manufacture of Therapeutically Qualified Cells for Cell Therapy.

Despite the great promise, cell therapy still faces practical challenges because of the scarcity of a reliable cell source. Herein, a bioinspired 3D dynamic culture system (CellMatrix) with rational structure, composite and function, was developed for improving cell supply. CellMatrix was composed of unique core-shell fibers with a core of black phosphorus-incorporated fibroin and a shell of sericin, which together formed a 3D silkworm cocoon-mimicking structure via a bottom-up fabrication technique. CellMatrix not only provided optimal engineered biomimetic niche to facilitate cell growth but exhibited good photothermal conversion to dynamically regulate cell fates. Importantly, cell-CellMatrix construct could be directly implanted into defected tissues and improved tissue remodeling. Meanwhile, CellMatrix displayed good ice resistance and thermal conductivity, which maximally maintained cell viability and proliferation after the freeze-thawing process, allowing for storing precious cells and cell-CellMatrix construct. Thus, CellMatrix represents an all-in-one biomimetic platform for the culture-production-storage of therapeutically qualified cells.

Cell Membrane Camouflaged Metal Oxide-Black Phosphorus Biomimetic Nanocomplex Enhances Photo-chemo-dynamic Ferroptosis.

Despite the availability of various treatment options, the inherent complexity of tumors significantly impairs therapeutic efficacy. Recently, combination treatments exhibited great anticancer potential due to low cross-resistance and good therapeutic additivity. Herein, a photoactive metal oxide-black phosphorus biomimetic nanocomplex (photophage) is developed for improving the antitumor combination of ferroptosis and photodynamic therapy (PDT). The photophage is composed of M1 macrophage membrane camouflaged MnO2 and Fe3O4 nanoparticles anchored black phosphorus nanosheets (BPNs), which together trigger a synergistic antitumor action. Fe3O4 acts as an iron source to activate Fenton-reaction-dependent ferroptosis, which can be further strengthened by BPN-mediated PDT. Besides the original antitumor effects, PDT also generates reactive oxygen species to enhance lipid peroxidation and glutathione depletion, which in turn reinforce ferroptosis and PDT efficacy. Importantly, MnO2 can in situ generate oxygen to relieve tumor hypoxia and consequently leverage cell behaviors to improve therapeutic responses. Particularly, M1 macrophage membrane modification endows the photophage with good tumor targeting capability and tumor penetration, which promote synergistic ferroptosis and PDT to destroy tumors while reducing systemic side effects, resulting in the prolonged survival of tumor-bearing mice. Therefore, we present a biomimetic nanoplatform for overcoming tumor barriers and advancing tumor-targeted treatment.

Design of robust superamphiphobic surfaces with enlarged area fractions: the considerable role of Laplace pressure in dynamics of contact lines.

Superamphiphobic surfaces have attracted widespread attention because of their great potential for applications in biotechnology, optoelectronics, water/oil separation, etc. Re-entrant curvatures are widely reported to provide a metastable Cassie state for superamphiphobicity. For high contact angles, re-entrant surfaces with a small area fraction (f) are designed according to the Cassie equation. However, this will make the surfaces take high local pressures under a mechanical force and thus suffer from frangibility. Robustness and high repellency are seemingly mutually exclusive. Herein, contrary to Cassie's equation, we show that high contact angles (>150°) with a large f (69.4%) of water and oleic acid can be achieved by utilizing a large upward Laplace pressure with narrow and parallel channel geometries. We deeply studied the effect of Laplace pressure on superamphiphobicity and suppose that the larger upward Laplace pressure stops the droplet earlier and pins the contact line at a higher position, providing a higher contact angle. The similar effect of viscous force well supports our explanation. These findings enable us to obtain robust and durable superamphiphobic surfaces with an enlarged area fraction and simple re-entrant microstructures. Our work may open up design strategies for robust superamphiphobic surfaces with practical applications.

Photoactive "Bionic Virus" Robustly Elicits the Synergy Anticancer Activity of Immunophotodynamic Therapy.

Coronavirus represents an inspiring model for designing drug delivery systems due to its unique infection machinery mechanism. Herein, we have developed a biomimetic viruslike nanocomplex, termed SDN, for improving cancer theranostics. SDN has a unique core-shell structure consisting of photosensitizer chlorin e6 (Ce6)-loaded nanostructured lipid carrier (CeNLC) (virus core)@poly(allylamine hydrochloride)-functionalized MnO2 nanoparticles (virus spike), generating a virus-mimicking nanocomplex. SDN not only prompted cellular uptake through rough-surface-mediated endocytosis but also achieved mitochondrial accumulation by the interaction of cationic spikes and the anionic mitochondrial surface, leading to mitochondria-specific photodynamic therapy. Meanwhile, SDN could even mediate oxygen generation to relieve tumor hypoxia and, consequently, improve macrophage-associated anticancer immune response. Importantly, SDN served as a robust magnetic resonance imaging (MRI) contrast agent due to the fast release of Mn2+ in the presence of intracellular redox components. We identified that SDN selectively accumulated in tumors and released Mn2+ to generate a 5.71-fold higher T1-MRI signal, allowing for effectively detecting suspected tumors. Particularly, SDN induced synergistic immunophotodynamic effects to eliminate malignant tumors with minimal adverse effects. Therefore, we present a novel biomimetic strategy for improving targeted theranostics, which has a wide range of potential biomedical applications.

High rate capabilities and remarkably cycle-stable flexible pseudocapacitors based on nano-coralloid arrays with sulfide vacancies enhanced Ni-Co-S nanoparticle covering.

Both poor electron conductivity and low ion diffusion of electrode materials are two main issues limiting the rate performance of pseudocapacitors. The present work reports the design and fabrication of hierarchically nano-architectured electrodes consisting of sulfide vacancies enhanced Ni-Co-S nanoparticle covering bent nickel nano-forest (BNNF). We propose new insight into vastly increased ion-accessible active sites and fast charge storage/delivery enhanced the reaction kinetics. The Ni-Co-S@BNNF electrode exhibits extremely high rate performance with 90.1% capacity retention from 1 to 20 A g-1, and even still remains 83.6% capacity at 40 A g-1, much superior to reported NiCo2S4-based electrodes. The high rate performance is attributed to the unique nano-architecture providing increased ion availability of electrochemically active sites and high conductivity for fast electron transport. Especially the electrode achieves remarkable long-term cycle stability with more than 100% initial capacity value after 5000 cycles at 5 A g-1and exhibits excellent cycle reversibility even at 20 A g-1. Goog cycle stability should be attributed to the sulfide vacancies in Ni-Co-S nano-branches and the electrode architecture sustaining structural strain during fast redox reactions. An asymmetric pseudocapacitor applying such electrode achieves a high energy density of 99.9 W h kg-1and exhibits superior cycling stability at a high current density of 20 A g-1. This study underscores the potential importance of developing nanoarrays covered with highly redox-active materials with increasing ions/charge kinetics for energy storage.

Non-Iridescent Metal Nanomesh with Disordered Nanoapertures Fabricated by Phase Separation Lithography of Polymer Blend as Transparent Conductive Film.

Metallic nanomesh, one of the emerging transparent conductive film (TCF) materials with both high electrical conductivity and optical transmittance, shows great potential to replace indium tin oxide (ITO) in optoelectronic devices. However, lithography-fabricated metallic nanomeshes suffer from an iridescence problem caused by the optical diffraction of periodic nanostructures, which has negative effects on display performance. In this work, we propose a novel approach to fabricate large-scale metallic nanomesh as TCFs on flexible polyethylene terephthalate (PET) sheets by maskless phase separation lithography of polymer blends in a low-cost and facile process. Polystyrene (PS)/polyphenylsilsequioxane (PPSQ) polymer blend was chosen as resist material for phase separation lithography due to their different etching selectivity under O2 reactive ion etching (RIE). The PS constituent was selectively removed by O2 RIE and the remained PPSQ nanopillars with varying sizes in random distribution were used as masks for further pattern transfer and metal deposition process. Gold (Au) nanomeshes with adjustable nanostructures were achieved after the lift-off step. Au nanomesh exhibited good optoelectronic properties (RS = 41 Ω/sq, T = 71.9%) and non-iridescence, without angle dependence owing to the aperiodic structures of disordered apertures. The results indicate that this Au nanomesh has high potential application in high-performance and broad-viewing-angle optoelectronic devices.

Vertically Aligned and Ordered Arrays of 2D MCo2S4@Metal with Ultrafast Ion/Electron Transport for Thickness-Independent Pseudocapacitive Energy Storage.

Pseudocapacitance holds great promise for energy density improvement of supercapacitors, but electrode materials show practical capacity far below theoretical values due to limited ion diffusion accessibility and/or low electron transferability. Herein, inducing two kinds of straight ion-movement channels and fast charge storage/delivery for enhanced reaction kinetics is proposed. Very thick electrodes consisting of vertically aligned and ordered arrays of NiCo2S4-nanoflake-covered slender nickel columns (NCs) are achieved via a scalable route. The vertical standing ∼5 nm ultrathin NiCo2S4 flakes build a porous covering with straight ion channels without the "dead volume", leading to thickness-independent capacity. Benefiting from the architecture acting as a "superhighway" for ultrafast ion/electron transport and providing a large surface area, high electrical conductivity, and abundant availability of electrochemical active sites, the NiCo2S4@NC-array electrode achieves a specific capacity up to 486.9 mAh g-1. The electrode even can work with a high specific capacity of 150 mAh g-1 at a very high current density of 100 A g-1. In particular, due to the advanced structure features, the electrode exhibits excellent flexibility with a unexpected improvement of capacity when being largely bent and excellent cycling stability with an obvious resistance decrease after the cycles. An asymmetric pseudocapacitor applying the NiCo2S4@NC-array as a positive electrode achieves an energy density of 66.5 Wh kg-1 at a power density of 400 W kg-1, superior to the most reported values for asymmetric devices with NiCo2S4 electrodes. This work provides a scalable approach with mold-replication-like simplicity toward achieving thickness-independent electrodes with ultrafast ion/electron transport for energy storage.

Polyvinyl alcohol: a high-resolution hydrogel resist for humidity-sensitive micro-/nanostructure.

A high-resolution nanopatterning technique is desirable with the present rapid development of hydrogel nanodevices. Here, we demonstrate that polyvinyl alcohol (PVA), a popular polymeric hydrogel, can function as the negative-tone resist for electron beam lithography (EBL) with a resolution capability as narrow as 50 nm half-pitch. Furthermore, the hydrophilic groups of PVA are stable after EBL exposure, and thus the pattern still shows rapid responsivity to humidity change. An aqueous nanopatterning process including dissolution, spin-coating and development is setup, which is friendly for organic device fabrication free of organic solvent. This high-resolution nanopatterning technique with PVA is helpful for the design and realization of hydrogel-related nanodevices in the future.

Controllable Subtractive Nanoimprint Lithography for Precisely Fabricating Paclitaxel-Loaded PLGA Nanocylinders to Enhance Anticancer Efficacy.

Nanoimprint lithography presents a new strategy for preparing uniform nanostructures with predefined sizes and shapes and has the potential for developing nanosized drug delivery systems. However, the current nanoimprint lithography is a type of an additive nanofabrication method that has limited potential due to its restricted template-dependent innate character. Herein, we have developed a novel subtractive UV-nanoimprint lithography (sUNL) for the scalable fabrication of PLGA nanostructures with variable sizes for the first time. sUNL can not only fabricate a variety of predefined nanostructures by simply utilizing different nanoimprint molds but also precisely prepare scalable nanocylinders with different length to diameter ratios. Particularly, sUNL can fabricate paclitaxel-loaded PLGA nanocylinders (PTX-PLGA NCs) with high drug-loading rate of 40% and long storage stability over a year. We demonstrate that PTX-PLGA NCs target clathrin- and caveolae-mediated cell transport pathways and display increased cellular uptake, in comparison to traditional PTX-loaded PLGA nanoparticles (PTX-PLGA NPs), leading to enhanced anticancer effects. Therefore, sUNL represents a promising nanofabrication method for efficiently developing predefined drug delivery systems.

An octopus-mimic PEGylated peptide as a specific integrin αvß3 inhibitor for preventing tumor progression.

We have developed a multivalent PEGylated RWrNR, named octopus-R, which exhibits good water solubility, biostability, biocompatibility and cancer targeting ability, endowing it with high anticancer potential. Octopus-R represents a promising theranostic agent and holds great potential for improving the management of malignant tumors.