ATP2A2 and type 2 diabetes mellitus: In the present study, the deficiency of SERCA2 expression observed in T2D osteocytes contributes to low levels of Ca2+ stored in the ER, which consequently incapacitates osteocytes from releasing/re-uptaking Ca2+ vigorously during each Ca2+ transient cycle, thereby resulting in attenuated Ca2+ signatures in response to external mechanical loading.