Significantly increased expression of STIM1, STIM2, Orai1, and Orai2 were observed in patients with PCOS compared with controls (P = 0.037, P = 0.004, P ≤ 0.001, and P = 0.013, respectively), whereas the expression of Orai3 was decreased (P = 0.003). Here, STIM2 is linked to polycystic ovary syndrome.