FGFR1 and cancer: Regorafenib is a potent inhibitor of several different receptor tyrosine kinases with relevant targets in cancer on both, blood vessels and stromal cells (amongst them VEGFRs, PDGFRs and FGFRs) (15), whereas infigratinib is a potent, selective inhibitor of FGFR1-3, and >10-fold lower sensitivity towards FGFR4 found on both tumour and endothelial cells (19, 39).