In 2020, the first multicenter, randomized, placebo-controlled, phase II trial REACHIN reported that Regorafenib significantly increased median PFS (3.0 versus 1.5 months, P = 0.004) for unresectable cholangiocarcinoma in second- or subsequent-line setting, revealing that the angiogenesis drug regorafenib, as a multikinase inhibitor acting on VEGFR 1-3, platelet-derived growth factor receptor (PDGFR), FGFR, and other targets, showed good antitumor activity in biliary tumors (26). Here, PDGFRB is linked to cholangiocarcinoma.