STIM1 and cancer: The knockdown or deletion of STIM1β in U87 cells inhibited cell proliferation, cell cycle progression, migration, and tumor growth by arresting the cell cycle at the G1 phase, which prolongs the length of the cell cycle and decreases cell cycle reentry.[31] Interestingly, the silencing of STIM1 by RNAi in U251 glioblastoma cells has been shown to induce G0/G1 phase cell cycle arrest and inhibit tumorigenicity in nude mice.[14] STIM1 or ORAI1 deficiency has been reported to inhibit the proliferation and migration in several cancer types.