The present investigation provided the first evidence that: 1) SOCE is mediated by Stim1, Orai1, and TRPC1 in EPCs harvested from peripheral blood of RCC patients; 2) the up-regulation of Stim1, Orai1, and TRPC1 is associated to the higher amplitude of SOCE in these cells; and 3) similar to N-EPCs, selective inhibition of SOCE impairs RCC-EPC proliferation and in vitro tubulogenesis. This evidence concerns the gene STIM1 and renal cell carcinoma.