RBP4 concentrations higher than or equal to 50 μg/mL were found to be up to 100% sensitive for the diagnosis of ATTRV122I amyloidosis, although its specificity decreased to 38%, suggesting that RBP4 could provide 100% negative predictive value when used to rule out ATTRV122I amyloidosis (Arvanitis et al., 2017a; Table 1). This evidence concerns the gene RBP4 and amyloidosis.