GSTM1 and renal cell carcinoma: However, stratification into Caucasians and Asians revealed that the dual GSTM1-GSTT1-null genotype was associated with the onset of RCC in Asians, when compared to population-based controls (Asians: OR = 1.72, 95% CI: 1.24–2.38, P = 0.001; population-based controls: OR = 1.70, 95% CI: 1.25–2.32, P = 0.0007; Table 4).