Classification model: cross-validation image of Ab responses against HTLV-I. The HTLV-I–infected groups: Model 1, comparing HAM/TSP patients and ACs (A); Model 2, comparing HAM/TSP and ATL patients (B); and Model 3, comparing ATL patients and ACs (C) were modeled and classified in conjunction with sex, race, and age using the Ab responses for Gag, Env, and Tax. Left graphs show receiver operating characteristic curves with cross-validation in each model. Right graphs show a model score under training conditions. Green, red, and blue curves represent the model score of ACs, HAM/TSP patients, and ATL patients, respectively.