A representative ELISPOT is shown in Fig. 1A. Specifically, T‐cell responses to MAGE‐A1 were detected in 17% (1/6) and 31% (9/29) of patients with mixed germ cell tumors (mGCT) and seminoma respectively but were absent in patients with non‐seminomatous germ cell testicular tumors (NSGCTT) (Fig. 1B). Here, MAGEA1 is linked to seminoma.