Analysis of safety across four clinical studies revealed that elevations in alanine aminotransferase (ALT) or aspartate aminotransferase (AST) levels (>3× the upper limit of normal) occurred in 2.7% of patients who received pirfenidone (Valeyre et al., 2014), but there was a case report of drug-induced liver injury (DILI) and acute liver injury in patients who received pirfenidone. Here, GPT is linked to injury.