GPT and autosomal dominant polycystic kidney disease: A liver safety signal was detected in the TEMPO 3:4 clinical trial of tolvaptan for the treatment of patients with autosomal dominant polycystic kidney disease (ADPKD), in which there was an imbalance in the proportion of participants with alanine aminotransferase (ALT) levels more than three times the upper limit of normal (ULN) between the tolvaptan (4.4%) and placebo (1.0%) trial arms [1–3].