Calcium- and integrin-binding protein that plays a role in intracellular calcium homeostasis (By similarity). Acts as an auxiliary subunit of the sensory mechanoelectrical transduction (MET) channel in hair cells (By similarity). Essential for mechanoelectrical transduction (MET) currents in auditory hair cells and thereby required for hearing (By similarity). Regulates the function of hair cell mechanotransduction by controlling the distribution of transmembrane channel-like proteins TMC1 and TMC2, and by regulating the function of the MET channels in hair cells (By similarity). Required for the maintenance of auditory hair cell stereocilia bundle morphology and function and for hair-cell survival in the cochlea (By similarity). Critical for proper photoreceptor cell maintenance and function (By similarity). Plays a role in intracellular calcium homeostasis by decreasing ATP-induced calcium release (PubMed:23023331, PubMed:26173970, PubMed:26426422). {ECO:0000250|UniProtKB:Q9Z309, ECO:0000269|PubMed:23023331, ECO:0000269|PubMed:26173970, ECO:0000269|PubMed:26426422}. This is the function of CIB2 (calcium and integrin binding family member 2, ENSG00000136425).