SF3B4 and acute lymphoblastic leukemia: To determine if T‐ALL relapse evolves due to splicing deregulation, we performed pathway specific analysis of RNA‐seq data that reveled significant alterations in gene expression of many splicing factors in patients with relapse T‐ALL, including upregulation of Peptidyl‐Prolyl Isomerase Like‐1 (PPIL1), ALYREF and members of the SF3 family such as SF3B3, SF3B2, SF3B4, and SF3A1 (Figure 2A, Supplementary Figure S2A).