CDKN2A and Alzheimer disease: To determine whether Cdkn2a expression was driven specifically by NFTs, or whether AD‐associated Aβ protein deposition also increased Cdkn2a, we utilized 3xTgAD mice that acquire both AD‐associated pathologies with Aβ deposition and NFT onset at 6 and 18 months of age, respectively (Oddo et al., 2003).