UDCA was the most common medicine in patients with PFIC3 [44], and the PFIC3 patients with residual phosphatidylcholine secretion and MDR3 expression, especially those with missense variants, responded to UDCA in 70% of cases [45], and even in those with cirrhosis, UDCA could delay PFIC3 progression [12]. The gene discussed is ABCB4; the disease is Cirrhosis.