FGFR1 and Familial prostate cancer: On the one hand, transcriptomic and clinicopathological data indicate that FGFRL1 expression in prostate cancer, esophageal cancer, and small-cell lung cancer is associated with tumor progression and, in some cohorts, with patient outcome, suggesting biological roles that are at least partly distinct from those of classical FGFR1–4 [65,66,67].