Studies on large cohorts of t-MDS patients compared to p-MDS provided evidence about significant differences in their mutational profiles, such as TP53 and PPM1D mutations being clearly more frequent in t-MDS than in p-MDS; and ASXL1, TET2, SRSF2 and SF3B1 mutations being less frequent in t-MDS than in p-MDS [12,80,81]. This evidence concerns the gene PPM1D and myelodysplastic syndrome.