With this known fact, the Food and Drug Administration (FDA) produced guidelines indicating that ALT greater than 8× ULN, ALT greater than 5× ULN for two weeks, ALT greater than 3× ULN in addition to serum bilirubin greater than 2× ULN, more than 1.5× PT-INR, or symptoms of liver injury be used to diagnose severe hepatotoxicity with discontinuation of the offending drug [60]. This evidence concerns the gene GPT and injury.