FGFR4 and breast carcinoma: As the canonical FGF8 receptors FGFR2c and FGFR3c are expressed at low level in breast cancer cells, it is possible that FGF8 acts in an autocrine manner on FGFR1 and FGFR4, which are instead present in the breast epithelium [160] (figures 2b and 4).