Increasing evidence links loss of calcium homeostasis in prostate cells and prostate cancer with alterations in the IP3 receptor in the endoplasmic reticulum and the T-type calcium channels, store-operated calcium channels Orai1 and STIM1, and the TRP channels TRPC1/C4, TRPM-8, and TRPV-6 in the plasma membrane [25, 32–35]. The gene discussed is ORAI1; the disease is prostate carcinoma.