To investigate whether inhibition of DNA methylation with the DNMT1 inhibitor DAC would increase CaSR expression, we initially treated all five colon tumor cell lines: Coga1A, Coga13, Caco2/AQ, HT29, and LT97 with 1 μM DAC for 72 hr (data not shown). Here, DNMT1 is linked to colonic neoplasm.