The effects of empiric antibiotic regimens in adults with non-ventilator-associated hospital-acquired pneumonia: A systematic review and network meta-analysis of randomized controlled trials.

BACKGROUND: The optimal empiric antibiotic regimen for non-ventilator-associated hospital-acquired pneumonia (HAP) is uncertain. OBJECTIVES: To compare alternative empiric antibiotic regimens in HAP using a network meta-analysis (NMA). METHODS: Data sources: Medline, EMBASE, Cochrane CENTRAL, Web of Science, and CINAHL from database inception to July 06, 2023. STUDY ELIGIBILITY CRITERIA: Randomized controlled trials (RCT). PARTICIPANTS: Adults with clinical suspicion of HAP. INTERVENTION: Any empiric antibiotic regimen versus another, placebo, or no treatment. ASSESSMENT OF RISK OF BIAS: Paired reviewers independently assessed risk of bias using a modified Cochrane tool for assessing risk of bias in randomized trials. METHODS OF DATA ANALYSIS: Paired reviewers independently extracted data on trial and patient characteristics, antibiotic regimens, and outcomes of interest. We conducted frequentist random-effects NMAs for treatment failure and all-cause mortality and assessed the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. RESULTS: 39 trials proved eligible. 30 RCTs involving 4,807 participants found low certainty evidence that piperacillin-tazobactam (RR compared to all cephalosporins: 0.65; 95% CI: 0.42, 1.01) and carbapenems (RR compared to all cephalosporins: 0.77; 95% CI: 0.53, 1.11) might be among the most effective in reducing treatment failure. The findings were robust to the secondary analysis comparing piperacillin-tazobactam vs antipseudomonal cephalosporins or antipseudomonal carbapenems vs antipseudomonal cephalosporins. 11 RCTs involving 2,531 participants found low certainty evidence that ceftazidime and linezolid combination may not be convincingly different from cephalosporin alone in reducing all-cause mortality. Evidence on other antibiotic regimens is very uncertain. Data on other patient-important outcomes including adverse events was sparse, and we did not perform network or pairwise meta-analysis. CONCLUSIONS: For empiric antibiotic therapy of adults with HAP, piperacillin-tazobactam might be among the most effective in reducing treatment failure in HAP. Empiric MRSA coverage may not exert additional benefit in reducing mortality in HAP. REGISTRATION: PROSPERO (CRD 42022297224).

Determination of permissive and restraining cancer-associated fibroblast (DeCAF) subtypes.

Cancer-associated fibroblast (CAF) subpopulations in pancreatic ductal adenocarcinoma (PDAC) have been identified using single-cell RNA sequencing (scRNAseq) with divergent characteristics, but their clinical relevance remains unclear. We translate scRNAseq-derived CAF cell-subpopulation-specific marker genes to bulk RNAseq data, and develop a single- sample classifier, DeCAF, for the classification of clinically rest raining and perm issive CAF subtypes. We validate DeCAF in 19 independent bulk transcriptomic datasets across four tumor types (PDAC, mesothelioma, bladder and renal cell carcinoma). DeCAF subtypes have distinct histology features, immune landscapes, and are prognostic and predict response to therapy across cancer types. We demonstrate that DeCAF is clinically replicable and robust for the classification of CAF subtypes in patients for multiple tumor types, providing a better framework for the future development and translation of therapies against permissive CAF subtypes and preservation of restraining CAF subtypes. Significance: We introduce a replicable and robust classifier, DeCAF, that delineates the significance of the role of permissive and restraining CAF subtypes in cancer patients. DeCAF is clinically tractable, prognostic and predictive of treatment response in multiple cancer types and lays the translational groundwork for the preclinical and clinical development of CAF subtype specific therapies.

Immune features are associated with response to neoadjuvant chemo-immunotherapy for muscle-invasive bladder cancer.

Neoadjuvant cisplatin-based chemotherapy is standard of care for muscle-invasive bladder cancer (MIBC). Immune checkpoint inhibition (ICI) alone, and ICI in combination with chemotherapy, have demonstrated promising pathologic response (

Decisional Conflict Among Patients Newly Diagnosed With Clinical T1 Renal Masses: A Prospective Study.

PURPOSE: Because multiple management options exist for clinical T1 renal masses, patients may experience a state of uncertainty about the course of action to pursue (ie, decisional conflict). To better support patients, we examined patient, clinical, and decision-making factors associated with decisional conflict among patients newly diagnosed with clinical T1 renal masses suspicious for kidney cancer. MATERIALS AND METHODS: From a prospective clinical trial, participants completed the Decisional Conflict Scale (DCS), scored 0 to 100 with < 25 associated with implementing decisions, at 2 time points during the initial decision-making period. The trial further characterized patient demographics, health status, tumor burden, and patient-centered communication, while a subcohort completed additional questionnaires on decision-making. Associations of patient, clinical, and decision-making factors with DCS scores were evaluated using generalized estimating equations to account for repeated measures per patient. RESULTS: Of 274 enrollees, 250 completed a DCS survey; 74% had masses ≤ 4 cm in size, while 11% had high-complexity tumors. Model-based estimated mean DCS score across both time points was 17.6 (95% CI 16.0-19.3), though 50% reported a DCS score ≥ 25 at least once. On multivariable analysis, DCS scores increased with age (+2.64, 95% CI 1.04-4.23), high- vs low-complexity tumors (+6.50, 95% CI 0.35-12.65), and cystic vs solid masses (+9.78, 95% CI 5.27-14.28). Among decision-making factors, DCS scores decreased with higher self-efficacy (-3.31, 95% CI -5.77 to -0.86]) and information-seeking behavior (-4.44, 95% CI -7.32 to -1.56). DCS scores decreased with higher patient-centered communication scores (-8.89, 95% CI -11.85 to -5.94). CONCLUSIONS: In addition to patient and clinical factors, decision-making factors and patient-centered communication relate with decisional conflict, highlighting potential avenues to better support patient decision-making for clinical T1 renal masses.

Detection of clade 2.3.4.4b highly pathogenic H5N1 influenza virus in New York City.

Highly pathogenic avian influenza viruses of the H5N1 clade 2.3.4.4b were detected in North America in the winter of 2021/2022. These viruses have spread across the Americas, causing morbidity and mortality in both wild and domestic birds as well as some mammalian species, including cattle. Many surveillance programs for wildlife as well as commercial poultry operations have detected these viruses. In this study, we conducted surveillance of avian species in the urban environment in New York City. We detected highly pathogenic H5N1 viruses in six samples from four different bird species and performed whole-genome sequencing. Sequencing analysis showed the presence of multiple different genotypes. Our work highlights that the interface between animals and humans that may give rise to zoonotic infections or even pandemics is not limited to rural environments and commercial poultry operations but extends into the heart of our urban centers.IMPORTANCEWhile surveillance programs for avian influenza viruses are often focused on migratory routes and their associated stop-over locations or commercial poultry operations, many bird species-including migratory birds-frequent or live in urban green spaces and wetlands. This brings them into contact with a highly dense population of humans and pets, providing an extensive urban animal-human interface in which the general public may have little awareness of circulating infectious diseases. This study focuses on virus surveillance of this interface, combined with culturally responsive science education and community outreach.

Detection of clade 2.3.4.4b highly pathogenic H5N1 influenza virus in New York City.

Highly pathogenic avian influenza viruses of the H5N1 clade 2.3.4.4b arrived in North America in the winter of 2021/2022. These viruses have spread across the Americas causing morbidity and mortality in both wild and domestic birds as well as some mammalian species, including cattle. Many surveillance programs in wildlife as well as commercial poultry operations have detected these viruses. Here we conducted surveillance of avian species in the urban environment in New York City. We detected highly pathogenic H5N1 viruses in six samples from four different bird species and performed full genome sequencing. Sequence analysis showed the presence of multiple different genotypes. Our work highlights that the interface between animals and humans that may give rise to zoonotic infections or even pandemics is not limited to rural environments and commercial poultry operations but extends into the heart of our urban centers.

Concomitant Biceps Tenodesis Does Not Compromise Arthroscopic Rotator Cuff Repair Outcomes.

PURPOSE: To compare outcomes of patients who underwent rotator cuff repair (RCR) with concomitant biceps tenodesis with those who underwent an isolated RCR. METHODS: Exclusion criteria included previous ipsilateral shoulder surgery, irreparable rotator cuff tears, rotator cuff arthropathy, calcific tendinitis, adhesive capsulitis requiring a capsular release, or advanced osteoarthritis of the glenohumeral joint. Patients were indicated for biceps tenodesis if they had any degree of tendon tearing, moderate-to-severe tenosynovitis, instability, or a significant degenerative SLAP tear. Primary outcome measures included American Shoulder and Elbow Surgeons score, Simple Shoulder Test, EuroQoL 5-Dimension 5-Level visual analog scale, EuroQoL 5-Dimension 5-Level, and a site-specific questionnaire, which focused on surgical expectations, satisfaction, and complications. Multivariate analysis of variance to analyze descriptive statistics and determine significant differences between the patient groups for subjective and objective outcome measures were performed. RESULTS: There were no significant differences for pain/visual analog scale (0.34 ± 0.09 vs 0.47 ± 0.09, P = .31), American Shoulder and Elbow Surgeons score (96.69 ± 0.87 vs 94.44 ± 0.91, P = .07), and Simple Shoulder Test (11.42 ± 0.17 vs 10.95 ± 0.18, P = .06) between the RCR with concomitant biceps tenodesis and isolated RCR at a minimum of 2 years' postoperatively. This is despite the RCR with concomitant biceps tenodesis group having significantly larger rotator cuff tears (4.25 ± 0.30 cm2 vs 2.80 ± 0.32 cm2, P = .001) than the isolated RCR group. CONCLUSIONS: This study revealed that concomitant biceps tenodesis does not compromise outcomes when compared with an isolated RCR at 2-year follow-up, despite this group having larger rotator cuff tears. LEVEL OF EVIDENCE: Level III, retrospective case study.

Optimizing Percutaneous Mitral Valvuloplasty for Rheumatic Mitral Stenosis　- Clinical Significance of Changes in Mitral Valve Area.

BACKGROUND: Percutaneous mitral valvuloplasty (PMV) is a standard treatment for severe rheumatic mitral stenosis (RMS). However, the prognostic significance of the change in mitral valve area (∆MVA) during PMV is not fully understood.Methods and Results: This study analyzed data from the Multicenter mitrAl STEnosis with Rheumatic etiology (MASTER) registry, which included 3,140 patients with severe RMS. We focused on patients with severe RMS undergoing their first PMV. Changes in echocardiographic parameters, including MVA quantified before and after PMV, and composite outcomes, including mitral valve reintervention, heart failure admission, stroke, and all-cause death, were evaluated. An optimal result was defined as a postprocedural MVA ≥1.5 cm2without mitral regurgitation greater than Grade II. Of the 308 patients included in the study, those with optimal results and ∆MVA >0.5 cm² had a better prognosis (log-rank P<0.001). Patients who achieved optimal results but with ∆MVA ≤0.5 cm² had a greater risk of composite outcomes than those with optimal outcomes and ∆MVA >0.5 cm² (nested Cox regression analysis, hazard ratio 2.27; 95% confidence interval 1.09-4.73; P=0.028). CONCLUSIONS: Achieving an increase in ∆MVA of >0.5 cm2was found to be correlated with improved outcomes. This suggests that, in addition to achieving traditional optimal results, targeting an increase in ∆MVA of >0.5 cm2could be a beneficial objective in PMV treatment for RMS.

FGFR inhibition augments anti-PD-1 efficacy in murine FGFR3-mutant bladder cancer by abrogating immunosuppression.

The combination of targeted therapy with immune checkpoint inhibition (ICI) is an area of intense interest. We studied the interaction of fibroblast growth factor receptor (FGFR) inhibition with ICI in urothelial carcinoma (UC) of the bladder, in which FGFR3 is altered in 50% of cases. Using an FGFR3-driven, Trp53-mutant genetically engineered murine model (UPFL), we demonstrate that UPFL tumors recapitulate the histology and molecular subtype of their FGFR3-altered human counterparts. Additionally, UPFL1 allografts exhibit hyperprogression to ICI associated with an expansion of T regulatory cells (Tregs). Erdafitinib blocked Treg proliferation in vitro, while in vivo ICI-induced Treg expansion was fully abrogated by FGFR inhibition. Combined erdafitinib and ICI resulted in high therapeutic efficacy. In aggregate, our work establishes that, in mice, co-alteration of FGFR3 and Trp53 results in high-grade, non-muscle-invasive UC and presents a previously underappreciated role for FGFR inhibition in blocking ICI-induced Treg expansion.

Targeting DHX9 Triggers Tumor-Intrinsic Interferon Response and Replication Stress in Small Cell Lung Cancer.

Activating innate immunity in cancer cells through cytoplasmic nucleic acid sensing pathways, a phenomenon known as "viral mimicry," has emerged as an effective strategy to convert immunologically "cold" tumors into "hot." Through a curated CRISPR-based screen of RNA helicases, we identified DExD/H-box helicase 9 (DHX9) as a potent repressor of double-stranded RNA (dsRNA) in small cell lung cancers (SCLC). Depletion of DHX9 induced accumulation of cytoplasmic dsRNA and triggered tumor-intrinsic innate immunity. Intriguingly, ablating DHX9 also induced aberrant accumulation of R-loops, which resulted in an increase of DNA damage-derived cytoplasmic DNA and replication stress in SCLCs. In vivo, DHX9 deletion promoted a decrease in tumor growth while inducing a more immunogenic tumor microenvironment, invigorating responsiveness to immune-checkpoint blockade. These findings suggest that DHX9 is a crucial repressor of tumor-intrinsic innate immunity and replication stress, representing a promising target for SCLC and other "cold" tumors in which genomic instability contributes to pathology. SIGNIFICANCE: One promising strategy to trigger an immune response within tumors and enhance immunotherapy efficacy is by inducing endogenous "virus-mimetic" nucleic acid accumulation. Here, we identify DHX9 as a viral-mimicry-inducing factor involved in the suppression of double-stranded RNAs and R-loops and propose DHX9 as a novel target to enhance antitumor immunity. See related commentary by Chiappinelli, p. 389. This article is featured in Selected Articles from This Issue, p. 384.

Mechanisms regulating the intracellular trafficking and release of CLN5 and CTSD.

Ceroid lipofuscinosis neuronal 5 (CLN5) and cathepsin D (CTSD) are soluble lysosomal enzymes that also localize extracellularly. In humans, homozygous mutations in CLN5 and CTSD cause CLN5 disease and CLN10 disease, respectively, which are two subtypes of neuronal ceroid lipofuscinosis (commonly known as Batten disease). The mechanisms regulating the intracellular trafficking of CLN5 and CTSD and their release from cells are not well understood. Here, we used the social amoeba Dictyostelium discoideum as a model system to examine the pathways and cellular components that regulate the intracellular trafficking and release of the D. discoideum homologs of human CLN5 (Cln5) and CTSD (CtsD). We show that both Cln5 and CtsD contain signal peptides for secretion that facilitate their release from cells. Like Cln5, extracellular CtsD is glycosylated. In addition, Cln5 release is regulated by the amount of extracellular CtsD. Autophagy induction promotes the release of Cln5, and to a lesser extent CtsD. Release of Cln5 requires the autophagy proteins Atg1, Atg5, and Atg9, as well as autophagosomal-lysosomal fusion. Atg1 and Atg5 are required for the release of CtsD. Together, these data support a model where Cln5 and CtsD are actively released from cells via their signal peptides for secretion and pathways linked to autophagy. The release of Cln5 and CtsD from cells also requires microfilaments and the D. discoideum homologs of human AP-3 complex mu subunit, the lysosomal-trafficking regulator LYST, mucopilin-1, and the Wiskott-Aldrich syndrome-associated protein WASH, which all regulate lysosomal exocytosis in this model organism. These findings suggest that lysosomal exocytosis also facilitates the release of Cln5 and CtsD from cells. In addition, we report the roles of ABC transporters, microtubules, osmotic stress, and the putative D. discoideum homologs of human sortilin and cation-independent mannose-6-phosphate receptor in regulating the intracellular/extracellular distribution of Cln5 and CtsD. In total, this study identifies the cellular mechanisms regulating the release of Cln5 and CtsD from D. discoideum cells and provides insight into how altered trafficking of CLN5 and CTSD causes disease in humans.

Hydroxyapatite-Coated Femoral Stems in Primary Total Hip Arthroplasty: An Updated Meta-Analysis.

BACKGROUND: Most primary total hip arthroplasties (THAs) performed in the United States utilize cementless fixation with porous or hydroxyapatite (HA) coating. A previous meta-analysis comparing HA-coated versus non-HA-coated stems in primary THA published in 2013 found no significant difference between the 2. However, an updated analysis of the current literature is needed to assess the potential benefit of HA-coated stems in primary THA. METHODS: Various libraries were searched through May 2022 according to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Studies included were randomized controlled trials comparing HA-coated femoral stems to non-HA-coated stems in primary THA. Outcomes included Harris Hip Score (HHS), endosteal bone formation, radiolucent lines, linear wear rate, revision for aseptic loosening, thigh pain, and heterotopic ossification. RESULTS: There were significantly fewer revisions for aseptic loosening (P = .004) and decreased postoperative thigh pain (P = .03) for patients who have with HA-coated stems. There was no significant difference in HHS (P = .20), endosteal bone formation (P = .96), radiolucent lines (P = .75), linear wear rate (P = .41), or heterotopic ossification (P = .71) between HA-coated and non-HA-coated stems. CONCLUSION: We found that HA-coated femoral stems in primary THA led to significantly fewer stem revisions for aseptic loosening and less postoperative thigh pain compared to non-HA-coated stems. These findings suggest HA-coated femoral stems should be preferred over non-HA-coated femoral stems in primary THA.

Outcomes of Severe Mitral Stenosis With the Revised Severity Criteria: Mitral Valve Replacement vs Percutaneous Mitral Valvuloplasty.

BACKGROUND: This study aimed to compare the outcomes, according to percutaneous mitral valvuloplasty (PMV) vs mitral valve replacement (MVR), of severe mitral stenosis (MS) with the updated criteria (MVA ≤ 1.5 cm2). METHODS: From the Multicenter Mitral Stenosis With Rheumatic Etiology (MASTER) registry of 3140 patients, we included patients with severe MS who underwent PMV or MVR between January 2000 and December 2021 except for previous valvular surgery/intervention, at least moderate other valvular dysfunction, and thrombus at the left atrium/appendage. Moderately severe MS (MS-MS) and very severe MS (VS-MS) were defined as 1.0 cm2 < MVA ≤ 1.5 cm2 and MVA ≤ 1.0 cm2, respectively. Primary outcomes were a composite of cardiovascular (CV) death and heart failure (HF) hospitalization. Secondary outcomes were a composite of primary outcomes and redo intervention. RESULTS: Among 442 patients (mean 56.5 ±11.9 years, women 77.1%), the MVR group (n = 260) was older, had more comorbidities, higher echoscore, larger left chambers, and higher right ventricular systolic pressure than the PMV group (n = 182). During a mean follow-up of 6.9 ± 5.2 years with inverse probability-weighted matching, primary outcomes did not differ, but the MVR group experienced fewer secondary outcomes (P = 0.010). In subgroup analysis of patients with MS-MS and VS-MS, primary outcomes did not differ. However, the MVR group in patients with VS-MS showed better secondary outcomes (P = 0.012). CONCLUSIONS: PMV or MVR did not influence CV mortality or HF hospitalization in both MS-MS and VS-MS. However, because of increased early redo intervention in the PMV group in VS-MS, MVR would be the preferable option without clear evidence of suitable morphology for PMV.

Near Complete Response to Platinum-based Systemic Chemotherapy in High-risk Upper Tract Urothelial Carcinoma With an ERBB2 Gene Mutation: A Case Report.

In bladder urothelial carcinoma, ERBB2 mutations have been associated with favorable response to platinum-based neoadjuvant chemotherapy. However, this association has not been reported in upper tract urothelial carcinoma (UTUC). We describe an excellent response to cisplatin-based chemotherapy in metastatic UTUC with an ERBB2 mutation. Our patient is a 54-year-old female with metastatic UTUC who received systemic cisplatin and gemcitabine. Postchemotherapy imaging demonstrated decreased size of pyelocaliceal mass and decreased retroperitoneal adenopathy compared to initial imaging. Surgical pathology from consolidative resection showed 3 mm residual renal tumor and no viable lymph node disease. Genomic testing demonstrated an ERBB2 gain of function mutation.

Spatial Relationships in the Tumor Microenvironment Demonstrate Association with Pathologic Response to Neoadjuvant Chemoimmunotherapy in Muscle-invasive Bladder Cancer.

BACKGROUND: Platinum-based neoadjuvant chemotherapy (NAC) is standard for patients with muscle-invasive bladder cancer (MIBC). Pathologic response (complete: ypT0N0 and partial:

Molecular cartography uncovers evolutionary and microenvironmental dynamics in sporadic colorectal tumors.

Colorectal cancer exhibits dynamic cellular and genetic heterogeneity during progression from precursor lesions toward malignancy. Analysis of spatial multi-omic data from 31 human colorectal specimens enabled phylogeographic mapping of tumor evolution that revealed individualized progression trajectories and accompanying microenvironmental and clonal alterations. Phylogeographic mapping ordered genetic events, classified tumors by their evolutionary dynamics, and placed clonal regions along global pseudotemporal progression trajectories encompassing the chromosomal instability (CIN+) and hypermutated (HM) pathways. Integrated single-cell and spatial transcriptomic data revealed recurring epithelial programs and infiltrating immune states along progression pseudotime. We discovered an immune exclusion signature (IEX), consisting of extracellular matrix regulators DDR1, TGFBI, PAK4, and DPEP1, that charts with CIN+ tumor progression, is associated with reduced cytotoxic cell infiltration, and shows prognostic value in independent cohorts. This spatial multi-omic atlas provides insights into colorectal tumor-microenvironment co-evolution, serving as a resource for stratification and targeted treatments.

Deciphering the Functional Roles of Individual Cancer Alleles Across Comprehensive Cancer Genomic Studies.

Cancer genome data has been growing in both size and complexity, primarily driven by advances in next-generation sequencing technologies, such as Pan-cancer data from TCGA, ICGC, and single-cell sequencing. Yet, discerning the functional role of individual genomic lesions remains a substantial challenge due to the complexity and scale of the data. Previously, we introduced REVEALER, which identifies groups of genomic alterations that significantly associate with target functional profiles or phenotypes, such as pathway activation, gene dependency, or drug response. In this paper, we present a new mathematical formulation of the algorithm. This version (REVEALER 2.0) is considerably more powerful than the original, allowing for rapid processing and analysis of much larger datasets and facilitating higher-resolution discoveries at the level of individual alleles. REVEALER 2.0 employs the Conditional Information Coefficient (CIC) to pinpoint features that are either complementary or mutually exclusive but still correlate with the target functional profile. The aggregation of these features provides a better explanation for the target functional profile than any single alteration on its own. This is indicative of scenarios where several activating genomic lesions can initiate or stimulate a key pathway or process. We replaced the initial three-dimensional kernel estimation with multiple precomputed one-dimensional kernel estimations, resulting in an approximate 150x increase in speed and efficiency. This improvement, combined with its efficient execution, makes REVEALER 2.0 suitable for much larger datasets and a more extensive range of genomic challenges.

Molecular characterization of plasmacytoid urothelial carcinoma and the impact on treatment implications.

Bladder cancer researchers and clinicians have increasingly viewed tumor biology through the lens of genomic and molecular alterations, drastically improving our knowledge of the underlying disease biology. This understanding has led to significant advances in treatment options that allow implementation of a personalized approach to cancer treatment. Large-scale genomic studies initially focused on the most common forms of bladder cancer. However, as genomic and molecular technologies become more widespread and are applied to less common variant histologies, we are gaining additional insight into the unique molecular and genomic characteristics driving the biology of variant histologies of bladder cancer. In this review, we summarize the current state of knowledge of molecular alterations underlying the distinct tumor biology of plasmacytoid urothelial carcinoma and how these alterations may impact treatment options.

Activation of KrasG12D in Subset of Alveolar Type II Cells Enhances Cellular Plasticity in Lung Adenocarcinoma.

We have previously identified alveolar type II cell as the cell-of-origin of KrasG12D-induced lung adenocarcinoma using cell lineage-specific inducible Cre mouse models. Using gain-of-function and loss-of-function genetic models, we discovered that active Notch signaling and low Sox2 levels dictate the ability of type II cells to proliferate and progress into lung adenocarcinoma upon KrasG12D activation. Here, we examine the phenotype of type II cells after Kras activation and find evidence for proliferation of cells that coexpress type I and type II markers. Three-dimensional organoid culture and transplantation studies determine that these dual-positive cells are highly plastic and tumor initiating in vivo. RNA sequencing analysis reveals that these dual-positive cells are enriched in Ras/MAPK, EGFR, and Notch pathways. Furthermore, the proliferation of these cells requires active Notch signaling and is inhibited by genetic/chemical Sox2 upregulation. Our findings could provide new therapeutic strategies to target KRAS-activated lung adenocarcinomas. SIGNIFICANCE: Identification of progenitor like tumor-initiating cells in KRAS-mutant lung adenocarcinoma may allow development of novel targeted therapeutics.