FGFR4 and breast carcinoma: Phenotypic and cell viability assessment following depletion of FGF19 also demonstrated that FGF19-mediated downstream signaling is crucial for the survival of basal-like breast cancer cells that co-express FGFR4 and FGF19 (MDA-MB-468 and HCC1937), as depletion of FGF19 by siRNA or anti-FGF19 monoclonal antibody (1A6) inhibits cell proliferation and induces apoptosis in these cells.