CYP1A1*2C SNP A4889G (rs1048943; exon7) (21, 22) leads to the substitution of Isoleucine(Ile) by Valine (Val) at position 462 in the protein,which results in a two-fold higher catalytic activityand mutagenicity due to its greater hydrophobicity.The association of the CYP1A1*2C polymorphismwith increased susceptibility to acute lymphoid leukemia(ALL) has been reported (23). Here, CYP1A1 is linked to acute lymphoblastic leukemia.