Overall, these data support that −7/del(7q) alone is an independent predictor of poor prognosis in MDS, validates that the isolated −7/del(7q) MDS cases investigated for their stem/progenitor cell hierarchies in our studies are representative for the patient group as a whole, and further establish that isolated −7/del(7q) MDS represents a high-risk MDS group distinct from −7/del(7q) cases with a complex karyotype and frequent TP53 mutations. Here, TP53 is linked to myelodysplastic syndrome.