We observed a significantly worse OS of STAG2-mutant MDS compared to cohesin/TP53-WT MDS (HR = 1.73, 95% CI = 1.4–2.14, median OS 30.3 vs. 69.8 months, p < 0.001, Fig. 4A), and a similar risk of leukemic transformation in STAG2- and TP53-mutant MDS cases (median AML-PFS of 15.4 months for STAG2 and 12.1 months for TP53, p = 0.3, DFCI cohort only, Fig. 4B). Here, STAG2 is linked to acute myeloid leukemia.