IFNG and neoplasm: However, when mice were inoculated with a dose of TC-1 cells that gave rise to 100% tumour incidence at day 25, castration did not increase the responsiveness of old mice to the low-dose vaccine (Fig. 6D), nor did it increase the levels of IFN-γ-producing cells (Fig. 6E) and cytotoxic activity (Fig. 6F).