TGFB1 and Hepatic fibrosis: In TGF‐β1‐treated HLOs, receptor‐ligand expression was observed involving PDGFB and PDGFRB, recapitulating an important hallmark of liver fibrosis in vivo (Kocabayoglu et al, 2015; Ying et al, 2017; Ramachandran et al, 2019).