https://www.selleckchem.com/products/tp-1454.html Dickkopf 1 (DKK1) is associated with tumor progression. However, whether DKK1 influences the tumor response to programmed cell death protein 1 (PD-1) blockade in colorectal cancers (CRCs) with deficient mismatch repair (dMMR) or microsatellite instability (MSI) has never been clarified. Tumor tissues from 80 patients with dMMR CRC were evaluated for DKK1 expression and immune status via immunohistochemistry. Serum DKK1 was measured in another set of 43 patients who received PD-1 blockade therapy. CT26 cells and dMMR CRC organoids were cocultured with T cells, and CT26-grafted BALB/c mice were also constructed. T-cell cytotoxicity was assessed by apoptosis assays and flow cytometry. The pathway through which DKK1 regulates CD8+ T cells was investigated using RNA sequencing, and chromatin immunoprecipitation and luciferase reporter assays were conducted to determine the downstream transcription factors of DKK1. Elevated DKK1 expression was associated with recurrence and decreased CD8+ T-cell infiltration D-1 blockade. Access to firearms among youth can increase the risk of suicide or other injury. In this study, we sought to estimate the population prevalence of adolescent perception of firearm access by demographic, geographic, and other individual health characteristics. The 2019 Healthy Kids Colorado Survey was an anonymous survey administered to a representative sample of high school students in Colorado. The survey was used to assess health behaviors and risk and protective factors. Analysis was conducted with weights to the state population of public high school students. In total, 46 537 high school students responded (71% student response rate; 83% school response rate). One in 5 students said it was "sort of easy" (11.1%) or "very easy" (8.8%) to access a handgun, with higher prevalence among male and older-aged youth and differences in racial and/or ethnicity groups. There were geographic differences such tha