PFDN4 and metabolic dysfunction-associated steatotic liver disease: In the HepG2 cell model of non-alcoholic-fatty-liver disease (NAFLD) [102], Qtn enhances tyrosine phosphorylation in the insulin signaling pathway and reduces the expression levels of the protein-1c-binding sterol regulatory element (SREBP-1c) compared to the control group (*G in Figure 2).