These complexes include the cleavage and polyadenylation specificity factor (CPSF) complex, the cleavage stimulation factor (CstF) complex, the cleavage factor I (CFIm) complex, and the CFIIm complex.11 The CPSF complex factor CPSF1 has been found to regulate the growth of several cancer subtypes by altering polyadenylation and splicing.9,12–14 Multiple other polyadenylation factors, such as CPSF3, CPSF4, CSTF2, CPSF6, NUDT21, PCF11, and CLP1, also function in cancer progression,15–29 highlighting that factors involved in mRNA polyadenylation may be a therapeutic vulnerability of cancer. The gene discussed is CSTF2; the disease is cancer.