Hydrogen has three naturally occurring isotopes, the stable forms; the Protium (1H), and Deuterium (2H), while the unstable radioactive form is Tritium (3H). Of the stable isotopes of hydrogen, Deuterium (D) and protium (H) have different chemical and physical properties. The ratio of Deuterium to hydrogen (D/H) in natural water is approximately 1:6600, and the natural fraction of Deuterium is approximately 0.0139–0.0151%. When the deuterium concentration is lower than 0.015% (150 ppm), the fraction is called ‘light water’ or deuterium-depleted water (DDW). D-concentration in living organisms is 12mmol/L. Recent research reported the anticancer potential of DDW in which the deuterium volume fraction in normal water (~150 parts per million) is reduced by 65%. Studies have demonstrated that incorporating low deuterium concentrations into conventional cancer therapy can significantly hinder the growth rate of various tumor cells and block metastasis and recurrence both in vitro and in vivo. The apoptosis-triggering was also studied both in vitro and in vivo. Deuterium depletion also influences proto-oncogenes such as c-Myc, H-Ras, and tumour suppressor genes like p53, thus significantly reducing growth when the carcinogen-exposed animals were given DDW to drink in a preclinical setting. However, the major missing understanding in the field is how DDW is effective as an anticancer agent. Hence, we propose to conduct a systemically planned experimental study to understand the molecular mechanisms underlying the anticancer potential of deuterium-depleted water.