Involved in cellular calcium homeostasis regulation. May participate in differentiation and apoptosis of keratinocytes. Overexpression induces apoptosis. Interacts with PTPN2. Interacts with microtubules. Interacts with VAPB. Present at high level in epidermis and seminiferous epithelium: while basal cells in the epidermis and spermatogonia show no perceptible amount, keratinocytes of suprabasal layers and differentiating first-order spermatocytes up to spermatids exhibit high expression.