High baseline NNTTR levels correlated with poor response to tafamidis treatment. (A) Responders (R, blue) had significantly lower baseline NNTTR levels than nonresponders (NR, red) (P = 0.0025, unpaired t test). (B) Responders (R, blue) had significantly lower baseline NNTTR/tTTR ratio than nonresponders (NR, red) (P = 0.0098, unpaired t test). (C) ROC curve for NNTTR with AUC = 0.6833.