The function of ITPR2 (inositol 1,4,5-trisphosphate receptor type 2, Ensembl gene identifier ENSG00000123104) is as follows. Inositol 1,4,5-trisphosphate-gated calcium channel that upon inositol 1,4,5-trisphosphate binding transports calcium from the endoplasmic reticulum lumen to cytoplasm. Exists in two states; a long- lived closed state where the channel is essentially 'parked' with only very rare visits to an open state and that ligands facilitate the transition from the 'parked' state into a 'drive' mode represented by periods of bursting activity (By similarity). .