FGFR2 and breast carcinoma: Since an isoform switch from FGFR2 IIIb to FGFR2 IIIc has been reported in a few breast cancer cell lines, and since this switch may contribute to tumor development, we explored whether rs2981578 genotype influences the alternative splicing of isoforms of FGFR2. The expected FGFR2-IIIb was detected in 14 epithelial cell cultures, and the expected FGFR2-IIIc was detected in 48 of 52 fibroblast cultures.