Our search for the mechanism underlying the selective silencing of the WT allele of FPGS in MTA-C3 cells led us to discover a heavily methylated CpG island in the region encompassing intron 11 through exon12 of the FPGS gene in human leukemia cell lines and in human peripheral white blood cell samples (i.e. healthy donor and an AML patient). Here, FPGS is linked to leukemia.