CHO-K1/Gqi5 is a CHO-K1 cell line stably expressing the chimeric Gqi5 alpha subunit protein which a chimeric Gq protein instead of the last five carboxyl-terminal amino acids from Gi. It is used as a host cell for transfection expression of Gi/o-coupled receptors, the constitutively expressed Gqi5 protein in the cells allows many transfected receptors which normally inhibit the cAMP pathway, to couple to Gq signal transduction and mobilize intracellular calcium. The cell line carries the hygromycin B resistance gene and is resistant to hygromycin B.