Significant reductions in STIM1 protein levels have been found in brain tissue in AD (Alzheimer’s disease) patients, while in PD patients, complexes formed by STIM1 and TRPC1 (transient receptor potential channel 1) can inhibit CaV1.3 channels, leading to disruption of neuronal Ca2+ homeostasis [45], ultimately leading to the development of PD symptoms. The gene discussed is CACNA1D; the disease is Alzheimer disease.