TGFB1 and cholangiocarcinoma: These models have enabled the identification of aberrant activation or functional remodeling of several key signaling pathways—including Notch, Wnt, TGF-β, PI3K/AKT, and Hippo—in diseases such as primary sclerosing cholangitis (PSC), biliary atresia (BA), cholangiocarcinoma (CCA), and gallbladder cancer (GBC) (Kosar, 2018; Meng et al., 2021; Yogo et al., 2023; Obata et al., 2023).