The emerging emetogenicity of trifluridine/tipiracil (TAS­102) from patient self-reporting: a multicenter, prospective, observational study.

BACKGROUND: Trifluridine/tipiracil (TAS-102) is an oral anticancer drug with adequate efficacy in unresectable colorectal cancer, but frequently also induces chemotherapy-induced nausea and vomiting (CINV). To investigate the occurrence of CINV and antiemetic therapy in patients with colorectal cancer treated with TAS-102 (JASCC-CINV 2001). METHODS: We conducted a multicenter, prospective, observational study in patients with colorectal cancer who received TAS-102 without dose reduction for the first time. Primary endpoint was the incidence of vomiting during the overall period. Secondary endpoints were the incidence of nausea, significant nausea, anorexia, other adverse events (constipation, diarrhea, insomnia, fatigue, dysgeusia) and patient satisfaction. Patient diaries were used for primary and secondary endpoints. All adverse events were subjectively assessed using PRO-CTCAE ver 1.0. and CTCAE ver 5.0. RESULTS: Data from 100 of the 119 enrolled patients were analyzed. The incidence of vomiting, nausea, and significant nausea was 13%, 67%, and 36%, respectively. The incidence of vomiting in patients with and without prophylactic antiemetic therapy were 20.8% and 10.5%, respectively. Prophylactic antiemetics were given to 24% of patients, of whom 70% received D2 antagonists. Multivariate Cox proportional hazards analysis showed that experience of CINV in previous treatment tended to be associated with vomiting (hazard ratio [HR]: 7.13, 95% confidence interval [CI]: 0.87-58.5, P = 0.07), whereas prophylactic antiemetic administration was not (HR: 1.61, 95 CI: 0.50-5.21, P = 0.43). With regard to patient satisfaction, the proportion of patients who were "very satisfied," "satisfied," "slightly satisfied" or "somewhat satisfied" was 81.8%. CONCLUSIONS: The low incidence of vomiting and high patient satisfaction suggest that TAS-102 does not require the use of uniform prophylactic antiemetic treatments. However, patients with the experience of CINV in previous treatment might require prophylactic antiemetic treatment.

Dexamethasone-sparing on days 2-4 with combined palonosetron, neurokinin-1 receptor antagonist, and olanzapine in cisplatin: a randomized phase III trial (SPARED Trial).

BACKGROUND: This study evaluated the non-inferiority of dexamethasone (DEX) on day 1, with sparing on days 2-4 in cisplatin-based chemotherapy. METHODS: Patients with malignant solid tumors who were treated with cisplatin (≥50 mg/m²) were randomly assigned (1:1) to receive either DEX on days 1-4 (Arm D4) or DEX on day 1 (Arm D1) plus palonosetron, NK-1 RA, and olanzapine (5 mg). The primary endpoint was complete response (CR) during the delayed (24-120 h) phase. The non-inferiority margin was set at -15%. RESULTS: A total of 281 patients were enrolled, 278 of whom were randomly assigned to Arm D4 (n = 139) or Arm D1 (n = 139). In 274 patients were included in the efficacy analysis, the rates of delayed CR in Arms D4 and D1 were 79.7% and 75.0%, respectively (risk difference -4.1%; 95% CI -14.1%-6.0%, P = 0.023). However, patients in Arm D1 had significantly lower total control rates during the delayed and overall phases, and more frequent nausea and appetite loss. There were no significant between-arm differences in the quality of life. CONCLUSION: DEX-sparing is an alternative option for patients receiving cisplatin; however, this revised administration schedule should be applied on an individual basis after a comprehensive evaluation. CLINICAL TRIALS REGISTRY NUMBER: UMIN000032269.

Public perceptions of physician-pharmaceutical industry relationships and trust in physicians.

BACKGROUND: In Japan, as elsewhere, physicians meet with and receive gifts from pharmaceutical representatives (PRs). This study aimed to clarify the Japanese public perceptions of physicians' relationships with PRs, examine the association between these perceptions and their trust in physicians, and compare the public's and physicians' awareness, acceptance, and perceptions of the influence of physician-PR relationships. METHODS: A cross-sectional, self-administered, anonymous, internet-panel survey was conducted involving 1,000 participants from the general public. The survey implementation was contracted to Cross Marketing Inc. RESULTS: The mean age of the 1000 participants was 44.8 years (standard deviation 18.3). Forty-eight percent were female. Many of our participants were unaware of certain physician-PR relationships. The public was more acceptable with physicians' receiving stationery and/or medical textbooks and attending promotional drug seminars at their workplaces compared with receiving meals at restaurants. Many thought that physicians' involvement in promotional activities influenced their prescribing habits and estimated that the majority of physicians received office stationery and meals from PRs. They were divided as to whether they would like to know about their physicians' relationships with the industry. Factors associated with higher trust in physicians included participants being 65 years or older, having a primary care physician, being in better health, the belief that physicians' involvement in promotional activities is acceptable, and their high estimate that physicians are not receiving gifts from PRs. Compared to the physicians, the public had lower awareness of and was more accepting of physicians' involvement in promotional activities. Meanwhile, the public believed that physician-PR relationships influenced physicians' prescribing habits more than the physicians themselves. CONCLUSION: Our survey provided insights into Japanese public perceptions of physician-pharmaceutical industry relationships and their impact on trust in physicians. Physicians should be aware of these perceptions and carefully consider how to foster appropriate relationships with the industry.

Changes in Japanese physicians' relationships with the pharmaceutical industry between 2008 and 2021: A national survey.

BACKGROUND: A national survey we conducted in 2008 showed that many Japanese physicians interacted with and received gifts from pharmaceutical representatives (PRs) and had a positive attitude toward relationships with PRs. The revised promotion code of the Japan Pharmaceutical Manufacturers Association in 2019 prohibited the provision of non-educational promotional aids including sticky notes, mouse pads, and calendars. During the COVID-19 pandemic in 2020, face-to-face meetings were socially restricted. This study assessed the extent of current Japanese physicians' involvement in pharmaceutical promotional activities and their attitudes toward relationships with PRs and to ascertain any changes between 2008 and 2021. We also examined the factors that predicted positive attitudes toward gifts from PRs. METHODS: From January to March 2021, we conducted a national mail survey of Japanese physicians in seven specialties: internal medicine, surgery, orthopedics, pediatrics, obstetrics-gynecology, psychiatry, and ophthalmology. RESULTS: There were 1636 participants and the response rate was 63.2%. Most physicians met face-to-face with PRs (78.8%), whereas only a minority received meals outside the workplace (4.5%). PRs were thought to have an important role in continuing medical education (66.1%) and to provide accurate information about new drugs (74.2%). Opinions were divided on the appropriateness of gifts from PRs. Most thought that stationery and meals provided by the industry did not affect prescribing behavior (89.7% and 75.8%, respectively). Factors that predicted a positive attitude toward gifts from PRs were male, orthopedic specialty vs. internal medicine, more interactions with PRs, a positive attitude toward informational value, and no rules banning meetings with PRs. CONCLUSION: Involvement in pharmaceutical promotional activities is still common among practicing physicians in Japan, although the extent of the involvement had declined. Rules banning meetings with PRs appear to continue being effective at limiting a physician's involvement with promotional activities and their critical attitudes toward gifts from PRs.

Impact of Corticosteroids for IrAEs on the Clinical Outcome of Immunotherapy in Patients With NSCLC.

BACKGROUND/AIM: The impact of corticosteroids for the treatment of immune-related adverse events (irAEs) on the antitumor effect of programmed cell death-1 (PD-1) inhibitor is unclear. PATIENTS AND METHODS: A total of 172 patients with non-small cell lung cancer (NSCLC) treated with PD-1 inhibitors were retrospectively reviewed. Patients were divided into four groups: those who did not develop irAEs [1] and those who developed irAE and were either not treated with corticosteroids [2] or treated with low [3] or high doses [4], and overall survival (OS) was analyzed by the time of corticosteroid treatment. Landmark analysis was performed using Cox proportional hazard model with time-dependent covariates. RESULTS: A high-dose steroid treatment within 60 days correlated with a significantly worse OS than that of the group with irAEs without steroids (p=0.004). Moreover, there was no significant difference in OS between the irAE without steroid and low-dose steroid groups. CONCLUSION: Early severe irAEs and high-dose corticosteroid treatment were poor prognostic factors in patients with NSCLC treated with PD-1 inhibitors.

A missense mutation in Kcnc3 causes hippocampal learning deficits in mice.

Although a wide variety of genetic tools has been developed to study learning and memory, the molecular basis of memory encoding remains incompletely understood. Here, we undertook an unbiased approach to identify novel genes critical for memory encoding. From a large-scale, in vivo mutagenesis screen using contextual fear conditioning, we isolated in mice a mutant, named Clueless, with spatial learning deficits. A causative missense mutation (G434V) was found in the voltage-gated potassium channel, subfamily C member 3 (Kcnc3) gene in a region that encodes a transmembrane voltage sensor. Generation of a Kcnc3G434V CRISPR mutant mouse confirmed this mutation as the cause of the learning defects. While G434V had no effect on transcription, translation, or trafficking of the channel, electrophysiological analysis of the G434V mutant channel revealed a complete loss of voltage-gated conductance, a broadening of the action potential, and decreased neuronal firing. Together, our findings have revealed a role for Kcnc3 in learning and memory.

Effects of glucokinase activator, DS-7309, on embryo-fetal developmental toxicity in rats and rabbits.

The toxicological effects of DS-7309, a glucokinase activator, on pregnancy and embryo-fetal development in rats and rabbits and maternal blood glucose levels were examined. DS-7309 was administered at 3, 10, or 100 mg/kg to rats from Days 7-17 of pregnancy or at 10, 30, or 100 mg/kg to rabbits from Days 6-18 of pregnancy. In rats, maternal hypoglycemia (approximately 50 mg/dL) was seen at 3 and 10 mg/kg, but it recovered 7 h after dosing, leading to no toxic changes. In contrast, continuous severe maternal hypoglycemia (approximately 40 mg/dL, ≥7 h), fetal eye anomalies, and decreased fetal body weight were noted at 100 mg/kg. In rabbits, no fetal anomalies were seen at 10 and 30 mg/kg where maternal blood glucose level dropped to approximately 60-90 mg/dL, but recovered by 7 h after dosing at the latest. In contrast, at 100 mg/kg, severe hypoglycemia (around 60 mg/dL) was maintained and did not recover until 24 h after dosing; it resulted in decreased fetal viability and increased fetal skeleton anomalies. These findings indicate that DS-7309 could lead to embryo-fetal toxicity in rats and rabbits, with such toxicity considered to be related to continuous severe maternal hypoglycemia.

Study protocol for SPARED trial: randomised non-inferiority phase III trial comparing dexamethasone on day 1 with dexamethasone on days 1-4, combined with neurokinin-1 receptor antagonist, palonosetron and olanzapine (5 mg) in patients receiving cisplatin-based chemotherapy.

INTRODUCTION: Dexamethasone (DEX) is administered for multiple days to prevent chemotherapy-induced nausea and vomiting for patients receiving highly emetogenic chemotherapy (HEC); however, its notorious side effects have been widely reported. Although our multicentre randomised double-blind comparative study verified non-inferiority of sparing DEX after day 2 of chemotherapy when combined with neurokinin-1 receptor antagonist (NK1-RA) and palonosetron (Palo) for patients receiving HEC regimen, DEX sparing was not non-inferior in patients receiving cisplatin (CDDP)-based HEC regimens in subgroup analysis. Recently, the efficacy of the addition of olanzapine (OLZ) to standard triple antiemetic therapy on HEC has been demonstrated by several phase III trials. This study aims to confirm non-inferiority of DEX sparing when it is combined with NK-1RA, Palo and OLZ in patients receiving CDDP-based HEC regimens. METHODS AND ANALYSIS: This is a randomised, double-blind, phase III trial. Patients who are scheduled to receive CDDP ≥50 mg/m2 as initial chemotherapy are eligible. Patients are randomly assigned to receive either DEX on days 1-4 or DEX on day 1 combined with NK1-RA, Palo and OLZ (5 mg). The primary endpoint is complete response (CR) rate, defined as no emesis and no rescue medications during the delayed phase (24-120 hours post-CDDP administration). The non-inferiority margin is set at -15.0%. We assume that CR rates would be 75% in both arms. Two hundred and sixty-two patients are required for at least 80% power to confirm non-inferiority at a one-sided significance level of 2.5%. After considering the possibility of attrition, we set our final required sample size of 280. ETHICS AND DISSEMINATION: The institutional review board approved the study protocol at each of the participating centres. The trial result will be presented at international conferences and published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: UMIN000032269.

Genetics of Circadian Rhythms.

In mammals, genetic influences of circadian rhythms occur at many levels. A set of core "clock genes" have been identified that form a feedback loop of gene transcription and translation. The core genetic clockwork generates circadian rhythms in cells throughout the body. Polymorphisms in both core clock genes and interacting genes contribute to individual differences in the expression and properties of circadian rhythms. The circadian clock profoundly influences the patterns of gene expression and cellular functions, providing a mechanistic basis for the impact of the genetic circadian system on normal physiological processes as well as the development of diseases.

A Prospective Trial Evaluating the Safety of a Shortened Infusion of Ramucirumab in Patients with Gastrointestinal Cancer.

LESSONS LEARNED: A shortened infusion of ramucirumab (from 60 to 20 minutes) was safe and feasible without infusion-related reactions.Twenty-minute infusions of ramucirumab can be an option for patients with no infusion-related reactions during the first 60-minute treatment. BACKGROUND: Ramucirumab is usually administered over 60 minutes, during which it is unlikely to cause infusion-related reactions (IRRs). This prospective study evaluated the safety of a shortened infusion of ramucirumab. METHODS: Patients who received their first dose of ramucirumab in a 60-minute infusion without developing IRRs were eligible and received their second ramucirumab dose for 20 minutes. The primary study endpoint was incidence of IRR during the first short-term infusion, and the secondary endpoints were incidence of IRR at any time and adverse events other than IRR. RESULTS: Of the 40 patients enrolled (median age, 68.5 years), 20 (55%) were male, 27 (67.5%) had stage IV gastric cancer, 25 (62.5%) received ramucirumab in combination with taxane-based chemotherapy, and 24 (60%) received only a single administration of ramucirumab prior to their enrollment. Notably, no IRR was observed during the first short-term infusion (IRR rate, 0%; 95% confidence interval [CI], 0%-0.72%). Among the 149 short-term infusions performed, there were no instances of IRRs or unexpected adverse events related to the treatment (Table 1). CONCLUSION: For patients without development of IRRs upon the first ramucirumab administration, shortening infusion time (from 60 to 20 minutes) is safe and feasible.

Period2 3'-UTR and microRNA-24 regulate circadian rhythms by repressing PERIOD2 protein accumulation.

We previously created two PER2::LUCIFERASE (PER2::LUC) circadian reporter knockin mice that differ only in the Per2 3'-UTR region: Per2::Luc, which retains the endogenous Per2 3'-UTR and Per2::LucSV, where the endogenous Per2 3'-UTR was replaced by an SV40 late poly(A) signal. To delineate the in vivo functions of Per2 3'-UTR, we analyzed circadian rhythms of Per2::LucSV mice. Interestingly, Per2::LucSV mice displayed more than threefold stronger amplitude in bioluminescence rhythms than Per2::Luc mice, and also exhibited lengthened free-running periods (∼24.0 h), greater phase delays following light pulse, and enhanced temperature compensation relative to Per2::Luc Analysis of the Per2 3'-UTR sequence revealed that miR-24, and to a lesser degree miR-30, suppressed PER2 protein translation, and the reversal of this inhibition in Per2::LucSV augmented PER2::LUC protein level and oscillatory amplitude. Interestingly, Bmal1 mRNA and protein oscillatory amplitude as well as CRY1 protein oscillation were increased in Per2::LucSV mice, suggesting rhythmic overexpression of PER2 enhances expression of Per2 and other core clock genes. Together, these studies provide important mechanistic insights into the regulatory roles of Per2 3'-UTR, miR-24, and PER2 in Per2 expression and core clock function.

Investigating toxicity specific to adjuvanted vaccines.

In an attempt to understand the unique toxicity of adjuvanted vaccines, we studied how toxicity develops over time following vaccine administration. In addition to on- and off-target toxicity typically observed with general pharmaceuticals, we observed toxicity associated with both the generation and the broad action of effectors (antibodies and/or cytotoxic T lymphocytes, CTLs). The impact on effector generation appears to be related to local tolerance specific to the adjuvant. The vaccine immune response by effectors serves to demonstrate species relevance as outlined in the recent WHO guideline on the nonclinical evaluation of adjuvanted vaccines. When regarded as pharmaceuticals that function at sites of local administration, adjuvants have inherent on- and off-target toxicity. On-target toxicity of the adjuvant is typically associated with effector generation, and could vary depending on animal species. Therefore, the use of species with sensitivity to adjuvants described in the WHO guidelines is required to evaluate the toxicity of the vaccine associated with effector generation. Changes in safety pharmacology endpoints would be considered off-target and further studies are conducted only if changes in these endpoints are observed in nonclinical or clinical studies. Thus our decision tree does not recommend the routine conduct of stand-alone safety pharmacology studies.

Effects of maternal hypoglycemia on fetal eye and skeleton development in rats.

The relationship between insulin-induced maternal hypoglycemia and teratogenicity was investigated in detail. We injected 4 different forms of insulin (insulin human, aspart, glargine, and detemir) subcutaneously at 1 or 2 dose levels to Sprague-Dawley rats from Days 6 to 11 of pregnancy, measured blood glucose levels, and conducted fetal examination. In the insulin human and aspart (low dose) groups, while severe hypoglycemia (approximately 50mg/dL) was seen, it lasted only 6h and no fetal anomalies were observed. Fetal axial skeleton anomalies were observed in the aspart (high dose) group, which exhibited intermediate-duration of severe hypoglycemia (9h). Eye and axial skeleton anomalies were observed in the glargine and detemir groups, which exhibited continuous severe hypoglycemia (≥9h). These results revealed that insulin-induced maternal hypoglycemia caused fetal eye and skeleton anomalies and the causative key factors were duration of maternal severe hypoglycemia.

Fibersol-2 induces apoptosis of Apc-deficient colorectal Cancer (SW480) cells and decreases polyp formation in Apc MIN mice.

The consumption of dietary fibers has been implicated with a lowered risk of human colorectal cancer. Proposed mechanisms involve alterations in the stool consistency, transit time, and formation of short-chain fatty acid by dietary fiber fermentation, and the reorganization of gut microbiota. Here we show that Fibersol-2, a digest-resistant maltodextrin, not only inhibits proliferation of colorectal SW480 cancer cell lines by increasing reactive oxygen species (ROS), but decreases the numbers of the adenoma count in Multiple Intestinal Neoplasia (MIN) mice carrying a mutation in the Adenomatous Polyposis Coli gene by 84 d of age. These observations provide direct evidence that Fibersol-2 intrinsically contains anti-cancer activity, independent of the intestinal metabolism and any potential interactions with the microbiota.

Dual attenuation of proteasomal and autophagic BMAL1 degradation in Clock Δ19/+ mice contributes to improved glucose homeostasis.

Circadian clocks orchestrate essential physiology in response to various cues, yet their mechanistic and functional plasticity remains unclear. Here, we investigated Clock(Δ19/+) heterozygous (Clk/+) mice, known to display lengthened periodicity and dampened amplitude, as a model of partially perturbed clocks. Interestingly, Clk/+ mice exhibited improved glycemic control and resistance to circadian period lengthening under high-fat diet (HFD). Furthermore, BMAL1 protein levels in Clk/+ mouse liver were upregulated compared with wild-type (WT) mice under HFD. Pharmacological and molecular studies showed that BMAL1 turnover entailed proteasomal and autophagic activities, and CLOCKΔ19 attenuated both processes. Consistent with an important role of BMAL1 in glycemic control, enhanced activation of insulin signaling was observed in Clk/+ mice relative to WT in HFD. Finally, transcriptome analysis revealed reprogramming of clock-controlled metabolic genes in Clk/+ mice. Our results demonstrate a novel role of autophagy in circadian regulation and reveal an unforeseen plasticity of circadian and metabolic networks.

Transmissible microbial and metabolomic remodeling by soluble dietary fiber improves metabolic homeostasis.

Dietary fibers are increasingly appreciated as beneficial nutritional components. However, a requisite role of gut microbiota in fiber function and the overall impact of fibers on metabolomic flux remain unclear. We herein showed enhancing effects of a soluble resistant maltodextrin (RM) on glucose homeostasis in mouse metabolic disease models. Remarkably, fecal microbiota transplantation (FMT) caused pronounced and time-dependent improvement in glucose tolerance in RM recipient mice, indicating a causal relationship between microbial remodeling and metabolic efficacy. Microbial 16S sequencing revealed transmissible taxonomic changes correlated with improved metabolism, notably enrichment of probiotics and reduction of Alistipes and Bacteroides known to associate with high fat/protein diets. Metabolomic profiling further illustrated broad changes, including enrichment of phenylpropionates and decreases in key intermediates of glucose utilization, cholesterol biosynthesis and amino acid fermentation. These studies elucidate beneficial roles of RM-dependent microbial remodeling in metabolic homeostasis, and showcase prevalent health-promoting potentials of dietary fibers.

Tumor suppression by resistant maltodextrin, Fibersol-2.

Resistant maltodextrin Fibersol-2 is a soluble and fermentable dietary fiber that is Generally Recognized As Safe (GRAS) in the United States. We tested whether Fibersol-2 contains anti-tumor activity. Human colorectal cancer cell line, HCT116, and its isogenic cells were treated with FIbersol-2. Tumor growth and tumorigenesis were studied in vitro and in vivo. Apoptotic pathway and generation of reactive oxygen species (ROS) were investigated. We discovered that Fibersol-2 significantly inhibits tumor growth of HCT116 cells by inducing apoptosis. Fibersol-2 strongly induces mitochondrial ROS and Bax-dependent cleavage of caspase 3 and 9, which is shown by isogenic HCT116 variants. Fibersol-2 induces phosphorylation of Akt, mTOR in parental HCT116 cells, but not in HCT116 deficient for Bax or p53. It prevents growth of tumor xenograft without any apparent signs of toxicity in vivo. These results identify Fibersol-2 as a mechanism-based dietary supplement agent that could prevent colorectal cancer development.

Investigation of the teratogenic potential of VLA-4 antagonist derivatives in rats.

Very late antigen-4 (VLA-4), which is concerned with cell-cell adhesion, plays important roles in development of the heart, and some VLA-4 antagonists cause cardiac anomalies. In this study, we evaluated the teratogenic potential of VLA-4 antagonist derivatives as screening, and investigated the conditions that induce cardiac anomalies. Seventeen compounds were orally administered to pregnant rats throughout the organogenesis period, and fetal examinations were performed. In addition, drug concentrations in the embryos were assayed. As a result, the incidence of ventricular septal defect (VSD) ranged from 0 to 100% depending on the compound. Plasma drug concentrations in the dams were related to increased incidence of VSD; however, these incidences were not increased when the concentration of the compound in the embryos at 24h after dosing was low. It is considered that continuous pharmacological activity in the embryo for more than 24h might disrupt closure of the ventricular septum.

Historical control data on developmental toxicity studies in rodents.

Historical control data on rodent developmental toxicity studies, performed between 1994 and 2010, were obtained from 19 laboratories in Japan, including 10 pharmaceutical and chemical companies and nine contract research organizations. Rats, mice, and hamsters were used for developmental toxicity studies. Data included maternal reproductive findings at terminal cesarean sections and fetal findings including the spontaneous incidences of external, visceral, and skeletal anomalies. No noticeable differences were observed in maternal reproductive data between laboratories. Inter-laboratory variations in the incidences of fetuses with anomalies appeared to be due to differences in the selection of observation parameters, observation criteria, classification of the findings, and terminology of fetal alterations. Historical control data are useful for the appropriate interpretation of experimental results and evaluation of the effects of chemical on reproductive and developmental toxicities.

Usf1, a suppressor of the circadian Clock mutant, reveals the nature of the DNA-binding of the CLOCK:BMAL1 complex in mice.

Genetic and molecular approaches have been critical for elucidating the mechanism of the mammalian circadian clock. Here, we demonstrate that the ClockΔ19 mutant behavioral phenotype is significantly modified by mouse strain genetic background. We map a suppressor of the ClockΔ19 mutation to a ∼900 kb interval on mouse chromosome 1 and identify the transcription factor, Usf1, as the responsible gene. A SNP in the promoter of Usf1 causes elevation of its transcript and protein in strains that suppress the Clock mutant phenotype. USF1 competes with the CLOCK:BMAL1 complex for binding to E-box sites in target genes. Saturation binding experiments demonstrate reduced affinity of the CLOCKΔ19:BMAL1 complex for E-box sites, thereby permitting increased USF1 occupancy on a genome-wide basis. We propose that USF1 is an important modulator of molecular and behavioral circadian rhythms in mammals. DOI:http://dx.doi.org/10.7554/eLife.00426.001.