STIM1 and acute lymphoblastic leukemia: Having established the role of CRAC and its pore-forming subunit Orai1 in pevonedistat-induced calcium influx and MEK/ERK activation in ALL, we examined the mechanistic interaction between Orai1 and the ER-membrane protein STIM1, which orchestrates Ca2+ influx by migrating to ER-plasma membrane appositions (puncta) to interact and open Orai1 [28].