GPT and cholestasis: Serum level of ALT is a clinical marker used to evaluate the presence of abnormal liver function [25]; this assay is considered the more specific marker for hepatic necrosis because ALT is normally found in the cytoplasm of the hepatocytes, whereas raised serum levels of ALP and γ-GTP are considered indicators of cholestasis because these enzymes are present on hepatocyte canalicular domain and the luminal domain of the bile duct epithelium [26].