The “Paris criteria” are the most common diagnostic tool for the “overlap syndrome” and include the following for PBC: (1) alkaline phosphatase (ALP) ≥ 2× upper normal limit (ULN) or gamma-glutamyl-transpeptidase (gamma-GT) ≥ 5× ULN; (2) presence of antimitochondrial antibodies (AMAs); (3) a liver biopsy specimen showing florid bile duct lesions. The gene discussed is GGTLC1; the disease is overlapping connective tissue disease.