Required for calcium-mediated regulation of ciliary beat frequency and mucociliary clearance in the airway. Might be involved in the regulation of intracellular calcium in tracheal epithelial cells. Interacts with LYPD3 and DAG1 (alphaDAG1). Found in the cytoplasm, which could include the endoplasmic reticulum. Expressed in the lung, in the ciliated cells of the airway epithelium (PubMed:25751668). Expression increased with differentiation of airway epithelial cells (PubMed:25751668). Not detected in the mucous cells (PubMed:25751668). Expressed in ciliated cells in the oviduct (PubMed:26170690). Also detected in stomach, colon, prostate and liver (PubMed:25751668). Expressed in breast, ovary, prostate and liver cancer (PubMed:26170690). Expression is associated with the level of differentiation of breast cancer (at protein level) (PubMed:26170690). Not induced as part of the cellular response to endoplasmic reticulum stress (PubMed:25751668). Up-regulated by androgens and by estrogens in prostate cancer cells (PubMed:23294566) Up-regulated by a hormone (estrogen-receptor alpha) independent mechanism in ovarian cancer (PubMed:22361111). Belongs to the AGR family.