The present report focused on the effects of genetic variation in NQO1, CYP2E1A, and NAT2 polymorphisms and their interaction with environmental factors, such as home exposure to fertilizers, insecticides, hydrocarbon derivatives (benzene, petroleum products, etc.), and parental tobacco smoking and wood smoking, among other variables in the risk of developing childhood ALL. This evidence concerns the gene NAT2 and acute lymphoblastic leukemia.