PDGFRA and Hepatic fibrosis: Considering that platelet-derived growth factor (PDGF)-BB is a key molecule in the process leading to liver fibrosis, it has been reported that PDGF-BB–treated HSCs release PDGF receptor-alpha (PDGFRα)-enriched exosomes, which promote HSC migration and liver fibrosis (Kostallari et al., 2018).