Purity ~99% (HPLC). A cell-permeable thienopyrimidine compound that competes against MLL (Mixed Lineage Leukemia) for menin binding (IC50 = 46 and 520nM, respectively, against MBM1 sequence MLL4-15 and MLL4-43 containing both MBM1 & MBM2) by targeting menin MLL-binding pocket with high affinity (KD = 22nM), effectively disrupting cellular menin and MLL-AF9 fusion interaction (by >90% at 12uM in MLL-AF9-expressing HEK293 cells). Shown to inhibit the oncogenic proliferation of four MLL translocation-harboring human leukemia cell lines (by >95% in 12 d at 6uM), but not non-MLL leukemia Kasumi-1 and HAL-01 lines (≤16% inhibition at 12uM), by downregulating MLL target genes expression via simultaneous hematopoietic differentiation induction and killing of non-differentiated population. Formula: C17H20F3N5S2 BULL; HCl Solubility: DMSO Primary Target: Menin