In this study, the authors also found that the absence of melatonin synthesis enhanced the expression of biliary senescence markers, including p16, p21, C‐C motif chemokine ligand 2 (CCL2) and senescence‐associated β galactosidase (SA‐β‐gal), leading to hepatic fibrosis progression (Chen et al., 2019) (Figure 4). The gene discussed is CCL2; the disease is Hepatic fibrosis.