GPT and Hepatic failure: A study from Liaw et al reported that subclinical and asymptomatic liver injury can be commonly induced by PTU.[42] Tamagno revealed that PTU treatment has a higher risk of hepatotoxicity than MMI.[43] According to the results from the report of Russo et al, PTU ranked the third leading cause of drug-induced liver failure requiring transplants with 23 cases receiving liver transplants between 1990 and 2007 in the United States.[44] This may be because PTU can lead to active metabolites, resulting in the injury of the hepatocellular and the increase of ALT in serum.