GPR55 and Alzheimer disease: Regarding LPI/PI, while activation of GPR55, a receptor for LPI, has been reported to improve the pathological condition of AD (Xiang et al., 2022), a GPR55 antagonist has been reported to attenuate inflammatory changes of the microglia (Saliba et al., 2018), as of macrophages (Kurano et al., 2021).