PTK2 and breast cancer: By taking a complementary approach and looking at genes previously shown to be differentially spliced in breast cancer we also observed a high level of concordance, for example Tenascin C, CD44, CD47, RELA, PTK2, ESR1, SYK, BRCA1, LARP1 and ADD39, 45, 46, 47, 48, 49, 50, 51, 52.