PTBP1 and cancer: PTBP1 is also a natural repressor of differentiation-specific alternative splicing events (Boutz et al., 2007, Kafasla et al., 2012, Keppetipola et al., 2012, Makeyev et al., 2007, Spellman et al., 2007, Yap et al., 2012), providing another possible explanation for its increased expression in cancer cells.