GPR55 and Alzheimer disease: The evidence regarding the effect of cannabinoid and cannabinoid-related receptors on MCs, macrophages and DCs (CB2R, GPR55, TRPV1, TRPA1), T-cells (CB2R, GPR55, TRPA1), and on neutrophils (GPR55) suggests the possibility that the manipulation of the inflammatory cell functions with endocannabinoids and cannabinoids could result in a novel approach to the treatment of AD.