U2AF1 and myelodysplastic syndrome: Singhal et al. have characterized the genetic abnormalities of 129 t-MN and observed that the mutational burden was similar in t-MN and in primary MDS (p-MDS); however, some notable differences exist in the mutational pattern between t-MN and p-MDS: (i) TP53 mutations are more frequent in t-MN than in p-MDS; (ii) SRSF2, SF3B1, U2AF1, CBL, and JAK2 mutations are less frequent in t-MN than in p-MDS [79].