B2M and Alzheimer disease: Since NCAM1 is a novel interacting partner of neuronal MHC-I-β2M complex (Fig. 3) and MHC-I-β2M is destabilized by Aβ oligomers and in AD brains (Figs. 1, 2), we speculated that the interaction of NCAM1 with MHC-I-β2M complex is also deregulated.