Indeed, patients with RAD21 and SMC1A/SMC3/PDS5B mutations trended towards a higher percentage of blasts in their diagnostic AML bone marrow biopsy compared to patients with STAG2 mutations (median morphology-defined blast count of 47% for RAD21 vs. 28% for STAG2-mutant AML, p = 0.11, Supplementary Fig. 3F, data available for the DFCI cohort only). Here, STAG2 is linked to acute myeloid leukemia.