Extracellular spermine blocked endogenous TRPM7 currents in rat basophilic leukemia (RBL) cells with an IC50 value of 2.3 μM, and 20 μM SKF-96365 was sufficient for complete inactivation of TRPM7 in RBL cells [75]. Here, TRPM7 is linked to acute basophilic leukemia.