MUC13 and nonpapillary renal cell carcinoma: Previous studies have found that the expression levels of MUCINs, including MUC1, MUC4, MUC12, MUC13, MCAM, and LAMA4 were correlated with poor survival of ccRCC patients, and/or promotion of tumor cell proliferation in vitro.13, 14, 15, 16, 17, 18