SRSF1 and breast cancer: To find out whether other RBPs regulate translation initiation of specific mRNAs during tumor progression, we first analysed by immunohistochemistry (IHC) the expression of several RBPs (hnRNP A1, hnRNP H, RBM9/FOX2, SRSF1/ASF/SF2, SRSF2/SC35, SRSF3/SRp20, SRSF7/9G8) in breast cancers.