We next analyzed the performance of a published clinical nomogram7 for patients with fully available clinical data (n = 40) and calculated the optimism-adjusted AUC using the bootstrapped procedure of Steyerberg et al.17 Using clinical variables alone (prechemotherapy tumor markers [alpha-fetoprotein, beta-human chorionic gonadotropin, lactate dehydrogenase]), residual mass size, percentage of mass shrinkage, and presence of teratoma elements in orchiectomy specimens), we calculated an AUC of 0.76. The gene discussed is AFP; the disease is teratoma.