JAK1/2 inhibitor baricitinib, an anti-inflammatory drug used to treat rheumatoid arthritis,621 rescues inflammatory biomarkers and attenuates cell death in a dose-dependent manner in vitro.622,623 A recent phase I/II clinical trial (ClinicalTrials.gov identifier: NCT05189106) targeting mild cognitive impairment, AD, and ALS has commenced to investigate the penetration of baricitinib into CSF at daily doses of 2 mg or 4 mg and the effects on inflammatory biomarkers in the CSF of patients at risk of AD or with ALS. This evidence concerns the gene JAK1 and rheumatoid arthritis.