TTR and early-onset autosomal dominant Alzheimer disease: Further, TTR is a serum transporter for thyroid hormones and retinol binding proteins that has been shown to be detrimental when misfolded and aggregated in various forms of amyloidosis, while also having evidence of protective effects in Alzheimer’s disease (AD) (Buxbaum et al., 2008; Sharma et al., 2019).