Through in vivo and in vitro experiments, it was further confirmed that exosomal miR-122-5p affected the level of ASK1 by targeting TNFRSF19, regulated the p38 MAPK signaling pathway, and inhibited the apoptosis, EMT, and fibrosis of IBECs, thus alleviating the pathological damage of PBC liver tissue. The gene discussed is TNFRSF19; the disease is primary biliary cholangitis.