An unconditional logistic regression was performed to find the association of H-RAS polymorphism with CML; we found an 18-fold increased risk of CML in carriers of the heterozygous CT genotype in comparison to wild-type carriers (TT) (P > 0.0001, OR: 18.4). This evidence concerns the gene HRAS and chronic myelogenous leukemia, BCR-ABL1 positive.