Many studies showed that Val allele of the GSTP1 Ile105Val polymorphism and the GSTP1 Val/Val genotype play an important role in individual susceptibility to T2D in different populations [4,30,31,32,33,34,35], but only one study investigated the relationship between GSTP1 gene polymorphism and HbA1c level in T2D patients [31]. The gene discussed is GSTP1; the disease is type 2 diabetes mellitus.