Immunologically there are two types of germ-cell cancer, namely that originating from the cells of the placenta, result of union of two germ cells of different genetic make-up, and that originating from the germ-cells of the gonads of both sexes. At present, there is a strong belief among scientists that the synergism between the cytotoxic effect of the drugs and the host's own immune interaction against the gestational choriocarcinoma is responsible for the therapeutic differences observed. If an immune reaction from the host against his own tumor is essential to facilitate a cure induced by chemotherapy, a new concept of immunization is warranted, since past experience had failed to induce an effective immunity against human cancer in most cases. It has been well established by others that immunization of experimental animals with a homologous testicular antigen plus Freud's adjuvant, will produce a species and organ specific immune reaction capable of destroying the testes germ-cells of the immunized animals. Since gonadal choriocarcinoma or other germ cell tumors originate from the germinal cell of the testicle, the purpose of this proposed investigation is to immunize patients, having an inoperable testicular germ-cell carcinoma with a human testicular antigen. The effect of immunization alone on the tumor will be assessed first. Afterwards, chemotherapy will also be used. The combined effects of chemotherapy plus immunization will be evaluated afterwards.