FGFR1 amplification has been shown to be associated with endocrine resistance and suppression of progesterone receptor expression in patients with hormone receptor-positive breast cancer (HR+BC), while FGFR1 blockade appears to revert endocrine resistance in cell lines with amplification and concomitant overexpression of FGFR12. The gene discussed is FGFR1; the disease is breast cancer.