U2AF1 and cancer: U2AF1 S34F is known to alter alternative splicing and polyadenylation of cancer-relevant genes (Przychodzen et al, 2013; Brooks et al, 2014; Ilagan et al, 2015; Okeyo-Owuor et al, 2015; Shirai et al, 2015; Yip et al, 2015, 2017; Fei et al, 2016; Park et al, 2016; Smith et al, 2019).