In this study, the up-regulated T-bet and ROR-γ and the down-regulated GATA-3 and Foxp3 in the Aβ1–42-injected hippocampus suggest a differentiation bias of CD4+ T-cells towards pro-inflammatory Th1 and Th17 cells away from anti-inflammatory Th2 and Treg cells in the AD brain. This evidence concerns the gene RORC and Alzheimer disease.