As TDH causes an increase in intracellular calcium level in intestinal epithelial cells through activation of calcium influx from extracellular environment and calcium-sensing receptor plays a vital role in influx of extracellular calcium, hence in this study we evaluate the potential of TDH in the down-regulation of colonic carcinoma cell proliferation (COLO 205). The gene discussed is TDH; the disease is colon carcinoma.