U2AF1 and anemia (phenotype): In addition, previous studies9,14,17 demonstrated that U2AF1 mutant is prone to anemia and thrombocytopenia, and S34F mutant of U2AF121 can have reduced erythropoiesis and abnormal granulo-monocyte differentiation via regulating the downstream target gene H2AFY and STRAP to form abnormal splicing.