RYR2 and Alzheimer disease: Recent report identified PTPRD association with the extent of neurofibrillary pathology in AD brain specimens (Chibnik et al., 2018; Uhl and Martinez, 2019), and also RYR3 gene for the RYR which functions to release the stored endoplasmic reticulum calcium ions (Ca2+) to increase intracellular Ca2+ concentration.