VEXAS patient CD34+ cells exhibited significantly lower IC_50 values and higher rates of apoptosis upon TAK-243 exposure than cells from healthy donors or myelodysplastic syndrome (MDS) controls, suggesting a broad therapeutic window in which UBA1-mutant clones are selectively targeted while sparing normal hematopoiesis (72). Here, UBA1 is linked to myelodysplastic syndrome.