PDHB and nonpapillary renal cell carcinoma: We also performed qRT-PCR experiments to detect the expression level of PDHB in ccRCC or normal kidney cell lines and found that PDHB was down-regulated in ccRCC cell lines (P<0.05; 786-O, 769-P, Caki-1 and A498) compared with normal kidney cell line HK2 (Figure 4L).