CDKN2B and acute lymphoblastic leukemia: Rafeeinia et al. [5] found that the levels of organochlorine pesticides in children with acute lymphoblastic leukaemia (ALL) were significantly higher than in healthy children, resulting in the hypermethylation of CDKN2B (cyclin-dependent kinase inhibitor 2B) and MGMT (O–6–methylguanine–DNA methyltransferase) genes.