FGFR4 and invasive ductal breast carcinoma: Finally, to determine whether FGFR4/FGF19 co-expression is present in primary breast tumors, we stained tissue microarrays of primary human breast cancer samples diagnosed with invasive ductal carcinoma (IDC) for FGFR4 and FGF19, and compared this with AKT phosphorylation (Figure 9).