As a result, we did not find a significant association between the GSTM1 null genotype and clinical TNM stages and Fuhrman grades of RCC (TNM stage I versus stage II + III + IV, stage I + II versus stage III + IV; Fuhrman grade 1 versus grade 2+3+4 and grade 1+2 versus grade 3+4). This evidence concerns the gene GSTM1 and renal cell carcinoma.