3α-Aminocholestane is an inhibitor of SH2 domain-containing inositol-5’-phosphatase 1 (SHP-1; IC50 = ~2.5 µM).1 It is selective for SHP-1 over SHP-2 and phosphatase and tensin homolog (PTEN; IC50s = >20 µM). 3α-Aminocholestane induces hyperactivation of the tyrosine kinase SYK in patient-derived Ph+ acute lymphoblastic leukemia (ALL) cells and selectively induces cytotoxicity in these cells over mature B cell lymphoma cells. It reduces leukemia burden and increases survival in a tyrosine kinase inhibitor-resistant patient-derived Ph+ ALL mouse xenograft model when administered at a dose of 50 mg/kg. 3α-Aminocholestane reduces cell viability of OPM2 multiple myeloma (MM) cells in a concentration-dependent manner and of RPMI8226 MM cells when used at concentrations greater than or equal to 12.5 µM.2 It halts the cell cycle at the G0/G1 or G2/M stages in the highly proliferative OPM2 or less proliferative RPMI8226 cell lines, respectively. It induces apoptosis via activation of caspase-3, caspase-9, and poly(ADP-ribose) polymerase (PARP) in OPM2 cells but not in RPMI8226 cells. 3α-Aminocholestane reduces tumor burden and increases survival in an OPM2 mouse xenograft model.WARNING This product is not for human or veterinary use.