With relevance to this study a range of different splicing factors have been shown to have altered expression in cancer tissues [18]; these include SRSF1 [19] and SRSF3 [20], which are upregulated in a wide range of cancers and have been identified as proto-oncogenes, and SRSF5 which is overexpressed in breast cancer [21]. Here, SRSF5 is linked to breast cancer.