FGFR4 and breast carcinoma: FGFR3 and FGFR4 gene amplifications are rare, with frequencies of 0.31 and 0.16% across various tumors.26Currently, no approved drugs specifically target FGFR amplification, but clinical trials are underway for lung cancer, gastric cancer, and breast cancer, suggesting potential future treatment targets.27, 28, 29