Yang L, et al. - In patients with rheumatoid arthritis (RA) with and without comorbid mild cognitive impairment (MCI), experts screened plasma to identify potential biomarkers useful in the differential diagnosis of comorbid MCI. They found that sonic hedgehog (SHH) and serum paraoxonase (TTR) could be candidate plasma biomarkers that could distinguish patients with RA and comorbid MCI from those without comorbid MCI.