CASP4 and nonpapillary renal cell carcinoma: Considering the potential role of the association between the immune response and CASP4 in ccRCC found in this study, as well as the reliable results obtained for immunotherapy in RCC, we further explored the infiltration of immune cells in ccRCC tumor tissues and the immune cells related to CASP4. CIBERSORT analysis of the proportion of TICs showed a positive correlation between CASP4 and activated CD4 memory T cells in patients with ccRCC.