This paper presents the influence of interactions between different genotypes (MnSOD Ala −9Val, ECSOD Arg213Gly, CAT −262C > T, GSTT1-null, GSTM1-null, GSTP1 Ile105Val, and Ala114Val and iNOS (CCTTT)n), between genotypes and smoking, and between genotypes and cumulative asbestos exposure on the risk of developing asbestosis. The gene discussed is GSTM1; the disease is asbestosis.