CNTF and Alzheimer disease: Within the HF (Figure 4A), for example, interleukin-8 (IL-8) another neuroinflammatory pathway, and ciliary neurotrophic factor (CNTF) signaling is upregulated in AD, SARS-CoV-2, and SARS-CoV-2-infected AD groups, while cAMP response element-binding protein (CREB) is also upregulated in the SARS-CoV-2 groups but downregulated in AD-only (Figure 4A).