To investigate the effect of the AD protective variant P522R on PLCγ2 enzyme function, we firstly measured production of 3[H] inositol phosphates in a radioactive assay as described [26] upon transient transfection of COS7 cells with pTriEx4-PLCG2 (common, “wild type” variant; PLCG2 522P) construct, the AD associated (P522R) construct, and with the D993G mutation (Ali5 [39]) construct. The gene discussed is PLCG2; the disease is Alzheimer disease.