FGFR2 and neoplasm: Despite their potential anti-tumor activity, they are ineffective at overcoming commonly acquired FGFR gatekeeper mutations (FGFR1 V561M, FGFR2 V564F, FGFR3 V555M, FGFR4 V550M/L) and other mutations including an FGFR1 N546K mutation and FGFR2 N550H mutations [4,73,74].