A 43-year-old male who had no history or family history of allergies was diagnosed with human epidermal growth factor receptor 2 (HER2)-negative gastric adenocarcinoma. He had been treated with 5 courses of SOX (S-1 40, 50, or 60 mg according to body-surface area, orally administered twice a day for 14 days with oxaliplatin 100 mg/m2 on day 1, every 3 weeks) as a first-line chemotherapy and 2 course of paclitaxel + ramucirumab (paclitaxel 80 mg/m2 on days 1, 8, 15 with 8 mg/kg ramucirumab on days 1 and 15, every 4 weeks) as a second-line chemotherapy. However, both treatments failed. He was referred to our department for third-line chemotherapy. He was 178 cm tall and weighed 78.3 kg. He had an Eastern Cooperative Oncology Group (ECOG) performance status of 2, body temperature of 36.5°C, blood pressure of 138/92 mm Hg, pulse rate of 67 beats per minute and SpO2 of 98% (atmospheric air). Physical examination revealed abdominal pain, back pain and leg oedema. He had taken vonoprazan fumarate, loxoprofensodium, rebamipide, adenine, naldemedine, magnesium oxide, fentanyl patches and a continuous infusion of oxycodone for pain. The baseline laboratory findings are shown in Table. A computed tomography (CT) scan showed left adrenal metastasis, peritoneal dissemination and suspected liver metastases. Eight days after the first administration of nivolumab, he developed a high fever (39.0°C), tachycardia, appetite loss, malaise, and elevated levels of bilirubin, liver enzyme, biliary enzyme and C-reactive protein (CRP). A CT scan revealed oedema of the Gleason sheath. Neither bile duct obstruction nor liver metastasis progression was revealed. Histopathological analysis of the liver revealed cholestatic liver injury. Immunohistochemical examination revealed CD8+ T lymphocyte and macrophage infiltration into the intrahepatic bile duct. There was no evidence of Epstein-Barr virus infection, cytomegalovirus infection or autoimmune disease. Although his blood culture was negative, sulbactam/cefoperazone was started empirically given the possibility of a biliary tract infection. As the levels of bilirubin, biliary enzyme and CRP increased on day 9, we started prednisolone (PSL) 80 mg (1 mg/kg/day) as a treatment for nivolumab-induced liver injury and cholangitis. His symptoms, including high fever, tachycardia, appetite loss and malaise, without any obvious infection, were similar to the symptoms of CRS that we have observed after TCR-Gene Transduced T Cell Transfer therapy []. The examination of his serum revealed marked elevation of the level of interferon (IFN)-γ elevation in the early phase and bimodal elevation of the level of TNF-α. His bilirubin level decreased temporarily but subsequently increased. On day 22, 1 g of methyl prednisolone was started for three days. However, his levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were increased. After adding mycophenolate mofetil 2 g daily to the PSL on day 27, T-bil, his levels of ALT and ALT decreased, but his levels of alkaline phosphatase (ALP) and gamma-glutamyl transferase (γ-GTP) continued to increase. Although his bilirubin level was improved after the addition of mycophenolate mofetil, his levels of AST and ALT increased again due to the progression of the liver metastases. He died of gastric cancer on day 105.