CTLA4 inhibitory strategies are established immune checkpoint inhibitors in malignant and nonmalignant inflammatory pathologies.16, 25, 49 However, there would be concern about the use of this immunotherapeutic strategy in ALF (eg, ipiluminab), given its significant side-effect profile (eg, colitis, dermatitis, and autoimmune hepatitis24) and potential risk in impairing hepatic regenerative responses. The gene discussed is CTLA4; the disease is colitis.