We retrieved 4 studies investigating the diagnostic performance of matrix metallopeptidase-7 (MMP-7)57–60, 2 investigating that of interleukin 33 (IL-33)19,56 and 3 investigating that of γ-glutamyl transferase (GGT)59,68,69 in the early differentiation of BA from non-BA; 3 studies evaluating that of aspartate aminotransferase to the platelet ratio index (APRi) for post-KPE prognosis (specifically, 2 for significant liver fibrosis and 3 for cirrhosis)61–63. This evidence concerns the gene MMP7 and Cirrhosis.