Journal of Toxicology substrates. Therefore, this study indicated that the inter- action of GSTP1 Val variant allele with GSTT1 or GSTM1 could aﬀect the elevation of blood cadmium concentration. 5. Conclusion These results suggested that polymorphisms of GSTP1 and combined genotypes of GSTP1 with GSTT1 and GSTM1 may be responsible for susceptibility to cadmium toxicity. The ﬁnding conﬁrms that interindividual variations in blood cadmium concentrations are not entirely attributable to en- vironmental exposure but also genetic background. From the point of view of toxicogenetics, some information of gene-environment and gene-gene interactions is provided by our ﬁndings. Further studies are needed to investigate the GSTT1, GSTM1, and GSTP1 mutations and their enzyme activities related to cadmium concentrations. 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