BIRC3 and B-cell chronic lymphocytic leukemia: BIRC3 encodes a ubiquitin ligase, and alternative cleavage and polyadenylation generates short (BIRC3-SU) and long (BIRC3-LU) 3′UTR mRNA isoforms, the latter of which is significantly upregulated in chronic lymphocytic leukemia (CLL) cells (Lee and Mayr, 2019).