Further analysis indicated that VHL mutations may elevate IL4I1 expression in tumors by modulating key transcription factors Hif-1a and SFMBT1, thus aggravating tumor progression.<h4>Conclusion</h4>Branched-chain amino acid metabolism and IL4I1 are pivotal in the progression of ccRCC. The gene discussed is SFMBT1; the disease is nonpapillary renal cell carcinoma.