RAC1 and colonic neoplasm: Indeed, in HCT-116 colon cancer cells TRPC1 and Rac1 are involved in a complex positive feedback loop in which EGF-induced SOCE activates both Rac1 and STIM1 through Akt pathway; in turn, STIM1 activation promotes translocation of TRPC1 and Orai1 into lipid rafts where SK3 is located and thereby triggers SOCE mediated by the complex SK3/TRPC1/Orai1.