mRNA levels of other factors such as TFPI-2, TSP1, AREG, and PAI-1, which were found to be regulated by V2R gene silencing in Caki1 cells (Figure 2A), were also increased in human ccRCC tumors compared to non-malignant kidney tissues (Figure 2D). This evidence concerns the gene SERPINE1 and nonpapillary renal cell carcinoma.