Even more interestingly, when we analyzed the phosphorylation status of FcγRIIb in the brains of AD patients, we found FcγRIIb phosphorylation on Tyr273 in the hippocampal tissues of five out of six AD patients (stage V and VI), but not in normal and mild cognitive impairment (MCI) patients (stage III) (Figure 3F). Here, FCGR2B is linked to Alzheimer disease.