The fraction of differentially spliced events (see the Materials and Methods section) between SF3B1 WT and SF3B1-mutant samples was enriched in Alt3’ss events both in CLL samples or MEC1 isogenic cell lines compared with the distribution of detected AS events (Fig 3A, Tables S4, and S5). This evidence concerns the gene SF3B1 and B-cell chronic lymphocytic leukemia.