FGF18 and nonpapillary renal cell carcinoma: As for tumor grade, high FGF18 expression was noted in 40 of 72 ccRCC T1 cases (55%) and in 3 of 10 ccRCC T2 cases (30%), which indicates that high ccRCC tumor grades correlate with low FGF18 expression (p = 0.045 < 0.05) (Figure 2B).