This review deals with the world's most important problem, which is hepatotoxicity. As a result of the distinctive location of the liver and its effect on all the substances entering the body and manufactured from it, the wastes resulting from metabolism, as well as its functional nature in the equation and removal of toxins. Therefore, the liver is one of the most influential and first organs in the human body because of the major functions it shows. Therefore, most of the research targets the liver through a number of chemicals, including carbon tetrachloride. Carbon tetrachloride is widely used, and its work depends on destroying hepatocytes through a group of chemical reactions with a group of chemical compounds for the liver such as fats and proteins, thus producing harmful substances such as free radicals, whose damage depends on the concentration and period of exposure to carbon tetrachloride. In order to determine the extent of the influence of the liver, there must be evidence. Our choice of Regucalcin was because it is closely related to several physiological functions, including: its role in maintaining the level of calcium on a regular basis in addition to its anti-programmed effects of cell death by inhibiting factors that break down the DNA strand by inhibiting the action of a group of enzymes. And other factors that destroy cells. Thus, the presence of Regucalcin inside and out of cells is evidence of the extent of damage and damage to hepatocytes and their dissolution. Therefore, Regucalcin can be considered a criterion for assessing the extent and degree of damage to the liver.