Although amplification of the fgfr4 gene has been found in 10% of breast cancers, we have previously shown that equivalent levels of FGFR-4 are present in the epithelial cells of malignant and non-malignant breast sections (Jaakkola et al, 1993; Coope et al, 1997). Here, FGFR4 is linked to breast carcinoma.