In addition to mostly unbalanced cytogenetic defects, mutations of a number of genes, including TET2 [12,13], UTX [14], CBL [15], EZH2 [16-18], ASXL1 [19-21], TP53 [7,22,23], RAS [24,25], IDH1/2 [26], and DNMT3A [27] have been implicated in the pathogenesis of MDS and may also modulate clinical features including responsiveness to LEN. The gene discussed is TP53; the disease is myelodysplastic syndrome.