PAPPA and Cognitive impairment: Using data from the Invecchiare in Chianti (InCHIANTI) study, Tanaka et al. [65] identified four plasma proteins (i.e., peptidase inhibitor 3 (PI3), trefoil factor 3 (TFF3), pregnancy-associated plasma protein A (PAPPA), and agouti-related peptide) that were associated with increased odds of cognitive impairment or dementia at baseline.