In the ongoing phase 1/2 BNT211-01 trial, CLDN6-specific chimeric antigen receptor (CAR)-T cells given with or without CARVac, a CAR-T cell-amplifying RNA vaccine, were well-tolerated and exhibited encouraging clinical activity in patients with relapsed or refractory CLDN6-positive solid tumors, with the highest response rate in patients with germ cell tumors. The gene discussed is CLDN6; the disease is germ cell tumor.