Since hypoxia can provide a connection between theextra-cellular environment, methylation of DNA, andcarcinogenesis, in the current study, the methylation levelsof BAX and BCL2 genes, as the critical genes involvedin cell death and survival, are evaluated via methylationspecific polymerase chain reaction (MSP) in MOLT-4cells, a T-ALL cell line, co-cultured with bone marrowMSCs under hypoxic condition. This evidence concerns the gene BCL2 and acute lymphoblastic leukemia.