FABP6 and nonpapillary renal cell carcinoma: Among the above target genes, FABP5 and FABP6 are in the same gene family, which are involved in the binding and transportation of fatty acids.[25] Since reprogramming of fatty acid metabolism is one of the distinct features for ccRCC, and FABP6 is expressed very low in ccRCC according to the transcriptomic data, we selected FABP5 for further investigations.