Among the ten c3USPs with the highest number of over-spliced tumour samples (Fig. 2b and Supplementary Table 4), the top candidate, CTNNB1 c3USP (3′ SP), was over-spliced in ~40% of tumour samples (2,251/5,577) in 10 of the 11 cancer types analysed (Fig. 2b,c and Extended Data Fig. 2g–i). Here, CTNNB1 is linked to cancer.