CD8A and neurodegenerative disease: Kelch-like ECH-associated protein 1 (KEAP1) forms part of E3 ubiquitin ligase, which regulates transcription factor NF-E2-related factor 2 (NRF2), and has an important role in responding to oxidative stress, and has been to linked to degenerative disease as well as an immunosuppressive tumor microenvironment with low infiltrating CD8+ T-cells [115,116].