Particularly, the subject with liver enzymes alteration was already affected by chronic hepatitis C and 3 weeks after guselkumab discontinuation, liver enzymes returned to lower values (AST: 160, ALT: 117) while the two subjects with PsA worsening had already been failed for the same reason different anti‐TNFs and one anti‐IL17s. Here, GPT is linked to chronic hepatitis C virus infection.