There was no an association between the dual-null genotype of individuals lacking both GSTM1– and GSTT1 and RCC risk in the overall population, Caucasians, or hospital-based controls (overall population: OR = 1.26, 95% CI: 1.00–1.59, P = 0.05; Caucasians: OR = 1.05, 95% CI: 0.89–1.23, P = 0.58; hospital-based controls: OR = 1.07, 95% CI: 0.91–1.25, P = 0.43; Fig. 4 for the overall population; Table 4). Here, GSTM1 is linked to renal cell carcinoma.