STIM1 and leukemia: Importantly, when overexpressed in rat basophilic leukemia cell line (RBL-2H3), which expresses a large, endogenous STIM1/Orai1-mediated SOCE (S3E Fig), TRIC-A significantly reduced the rate of Ca2+ influx as a measure of SOCE in classical Ca2+ readdition experiments by 44% (S3F Fig), though steady-state amplitudes of cytosolic Ca2+ elevation remained barely affected (S3G Fig).