The participants of this study were Caucasians.21 Results from another study involving 36 adult ALL patients from Turkey were similar for GSTM1 null genotype but were contradictory for GSTT1 as they showed negative association of GSTT1 deletion with ALL (OR, 0.2; 95% CI, 0.05-0.9).22 However, the sample size of these studies was not large enough to define the frequency of these alleles among ALL patients in population-specific manner. Here, GSTM1 is linked to acute lymphoblastic leukemia.