RKO GFPsh, RKO LSD1sh, and RKO CoRESTsh cells were treated with 5-aza-dC at 5 μm for 8 days. Then cells were released from 5-aza-dC by placement in standard culture medium for 20 or 30 additional days. Real-time PCR to quantify DNA methylation levels at MLH1 promoter was performed using the Methylight assay. PMR (Percentage of Methylation Reference) value was used to quantify the methylation levels at MLH1 promoter. (A) Methylight analysis of DNA methylation levels in the MLH1 promoter in RKO-GFPsh cells immediately after 5-aza-dC treatment (indicated as D-8), 20 days post treatment (indicated as R20), or 30 days post treatment (indicated as R30). (B) Methylight analysis of DNA methylation levels at the MLH1 promoter in RKO-LSD1sh cells as above. (C) Methylight analysis of DNA methylation levels at the MLH1 promoter in RKO-CoRESTsh cells. (D) Graphical summary of the data in (A), (B), and (C).