ADGRF5 and Alzheimer disease: Further investigation is needed to clarify the role of anti-NPB and anti-ADGRF5 antibodies in the pathophysiology, including functional assays to assess the effects of these antibodies on neurons or glial cells, passive immune challenge in AD animal models by administering anti-NPB or anti-ADGRF5 antibodies, and active immunization of animals with NPB or ADGRF5 antigens.