In addition, we studied the known CSC markers in ccRCC (CD44, CD133, and CD105), by in vitro immunohistochemistry staining and extrapolation of publicly available datasets like TCGA and CPTAC, with the goal of contributing to the search for novel molecular ccRCC signatures which may lead to diagnostic/prognostic evaluation of patients. This evidence concerns the gene CD44 and nonpapillary renal cell carcinoma.