ABCB4 and gallbladder disease 1: Understanding fundamental ABCB4 function in the liver, identifying new ABCB4 mutations and variants in patients with LPAC, and investigating potential gene therapy for ABCB4 deficiency in animal models should provide novel insights into the cellular, molecular, and genetic mechanisms underlying the onset and course of the disease, and will eventually open the door for early diagnosis and prevention of susceptible subjects and effective intervention for LPAC in patients.