PDGFRB and cholangiocarcinoma: Another promising VEGF inhibitor regorafenib (an oral multikinase inhibitor of VEGFR, PDGFR, and RAF kinases), in a phase II study of chemotherapy refractory advanced CCA patients, demonstrated mPFS of 3.6 months and mOS of 7.3 months (NCT02053376), highlighting its potential as a future treatment for patients with advanced CCA (Table 3) [78].