SFRP1 and nonpapillary renal cell carcinoma: The expression levels of these three up-regulated (PTP4A3, CAV2 and LAMA4) and three down-regulated genes (KCNJ1, SFRP1 and TCF21) evaluated by qRT-PCR were in line with those obtained by the expression array (in this case also considering the Fuhrman grade of the ccRCC; Figures 1 and 2).