IRS1 and breast cancer: The complete coding region and intron/exon boundaries of IRS-1 were investigated by automated sequencing in 12 BC cell lines (BT-20, BT-474, EVSA/T, MCF10A, MCF7, MDA-MB-134, MDA-MB-231, MDA-MB-365, MDA-MB-453, SK-BR-3, T47D, HCC1937).