Given the U2AF-homology motif (UHM) of PUF60 directly interacting with the WD-repeat of SAP155 (SF3B1)13, FIRΔexon2 is expressed in cancers when FIR pre-mRNA is affected by an autocatalytic mechanism through inhibiting the FIR-SAP155 splicing complex9. The gene discussed is SF3B1; the disease is cancer.