APOE and Alzheimer disease: To investigate TMCC2 in late onset AD and whether this is influenced by APOE genotype, we examined TMCC2 protein levels and cellular distribution in five APOE3 homozygous cognitively healthy human brains with an average age of 85 (range 82–90), five AD cases homozygous for APOE3 pathologically diagnosed with AD (Braak stages IV and V) with an average age of 77 (range 70–81), and five AD cases homozygous for APOE4 and diagnosed with AD (Braak stages V and VI), with an average age of 76 (range 71–89).