In order to unravel the molecular underpinnings of constitutive Ca2+ entry, we undertook protein knockdown of Stim1, Orai1 and Orai3, that have been involved in SOCE activation in cancer cells (Moccia et al., 2015; Vashisht et al., 2015), by using a siRNA silencing approach. The gene discussed is STIM1; the disease is cancer.