NFKB1 and primary biliary cholangitis: Interactions between specific members of the TNF pathway lead to the induction of apoptosis as well as activation of NFκB signaling; and in PBC, GWAS have identified 3 loci containing genes in TNFα signaling pathways.18, 20, 52 Macrophages from patients with PBC when stimulated with apoptotic bodies from BEC produce high levels of TNFα, with serum levels of TNFα reflecting the severity of intrahepatic damage.23, 53