Kaplan Meier survival analysis of overall survival in the APEX dataset. A 16-gene model derived from U133A/B data was applied to 156 relapsed myeloma patients treated in the APEX trial. The model identified 13.5% and 86.5% as high-risk and low risk, respectively. Overall survival estimates of one-year actuarial probabilities are 74% for low-risk disease (blue) versus 32% for high-risk (red; P = .001; HR = 2.52).