GSTM1 and chronic myelogenous leukemia, BCR-ABL1 positive: In the current study, a significant increase of 6.51‐, 3.17‐, and 4.40‐fold in the probability of having CML in individual who were both smokers and carried GSTM1/null, GSTT1/null and GSTP1M*genotypes, respectively, was indicated.