FUCA1 and nonpapillary renal cell carcinoma: Given that FUCA1, SLC16A12, CYFIP2, and LIMCH1 are lowly expressed in ccRCC tissues and that low expression of the four genes has a worse clinical prognosis, we further validated the expression of FUCA1, SLC16A12, CYFIP2, and LIMCH1 mRNA levels in 10 pairs of paired ccRCC and matched adjacent tissues.