PTBP1 and cancer: Examples of well-characterised families of splicing factors differentially expressed across several types of cancer are SR proteins, including SRSF1, SRSF3 and SRSF6 (Karni et al. 2007; Jia 2010; Anczuków et al. 2012; Jensen et al. 2014), and hnRNPs, such as hnRNPA1, hnRNPA2 and PTBP1 (David et al. 2010; Clower et al. 2010).