In the subgroup of clear cell carcinoma (n = 165, 16.4%), low SPHK1 expression was detected significantly more often (low SPHK1 in 88.5%, high SPHK1 in 11.5%, Table 1) than in all other histological subtypes (p < 0.001). This evidence concerns the gene SPHK1 and clear cell adenocarcinoma.