CYP4A11 and nonpapillary renal cell carcinoma: Regarding the immunohistochemical staining, western blot assays of CYP4A11 expression in the 4 matched pairs of ccRCC and nontumor tissue sections showed that ccRCC tumor samples expressed significantly lower levels of CYP4A (homologous to human CYP4A11 and 4A22) and CYP4A11 than the non-neoplastic tissue samples (p=0.029, p=0.114) (Fig. 2).