U2AF1 and chronic myelogenous leukemia, BCR-ABL1 positive: Moreover, in CD34+CD15− CP-CML cells, the expression of some genes (serine and arginine-rich splicing factor 1, 3, and 10 (SRSF1, SRSF3, SRSF10), U2 small nuclear RNA auxiliary factor 1 (U2AF1), muscleblind-like splicing regulator 3 (MBNL3) was strongly correlated (Supplemental Figure S1C,D).