SELENOM and renal cell carcinoma: SELM level was positively correlated to histological grade (P = 0.019) and tumor node metastasis (TNM) staging (P = 0.025), rather than age (P = 0.915), gender (P = 0.826), tumor size (P = 0.679), and tumor histology (P = 0.602) of RCC patients (Table 1).