PTBP1 and breast neoplasm: Importantly, we found that several RBPs, which are able to recognize the enriched sequences at 5′ and 3′ splice-sites and inside the AS cassette exons, were differentially expressed in breast cancer and during breast tumor progression, including PTBP1 [54,55], SRSF1 [28,30], and SRSF9 [30].