GSTP1 and Burkitt lymphoma: Karius et al. (2011) further investigated this mechanism and showed by bisulfite sequencing, methylation-specific PCR and combined bisulfite restriction analysis that the GSTP1 promoter was completely methylated in transcriptionally inactive in RAJI Burkitt’s lymphoma and MEG-01 chronic myeloid leukemia cell lines. In contrast, cell lines expressing GSTP1 exhibited an unmethylated and transcriptionally active promoter thus confirming a relationship between hypermethylation and repression of GSTP1 expression (Karius et al., 2011).