Exposure to a demethylating agent, 5-Aza (4 μM), for 7 days in vitro resulted in a change in the methylation status in the MSP1 and MSP2 regions of the promoters for both SPARC and INK4A(p16) in all four CRC cell lines (Figure 3B). This evidence concerns the gene CDKN2A and colorectal carcinoma.