Humans with Primary Biliary Cirrhosis (PBC), a disease characterized by the destruction of small bile ducts, exhibit signature auto-antibodies against mitochondrial Pyruvate Dehydrogenase Complex E2 (PDC-E2) that crossreact onto the homologous enzyme of Novosphingobium aromaticivorans, an ubiquitous alphaproteobacterium. This evidence concerns the gene DLAT and primary biliary cholangitis.