MRT-81 inhibits the differentiation of mesenchymal pluripotent C3H10T1/2 cells into alkaline phosphatase-positive osteoblasts induced by the Smo agonist SAG (0.1 µM), with an IC50 value of 64 nM^[1].

MRT-81, ranging from 1-1000 nM, potently antagonizes SAG (0.01 µM)-induced proliferation of rat granule cell precursors (GCPs) with an IC50 value of less than 10 nM^[1].

MRT-81 blocks BODIPY-cyclopamine (5 nM) binding to human Smo in a dose-dependent manner within a concentration range of 0 to 1000 nM for 2 hours at 37 °C, achieving an IC50 of 63 nM in HEK-hSmo cells^[1].