FLT3/CHK-IN-1 (Compound 18) is a dual inhibitor of FLT3/CHK1. FLT3/CHK-IN-1 is more than 1700 times more selective to c-KI T and greatly reduces hERG affinity with an IC50 value of 58.4 μM. FLT3/CHK-IN-1 inhibits tumor growth in mouse xenotransplantation models inoculated with MV-4-11 cells[1].