In the tumor experiments, the mice were immunized with the F-MuLV Env SU+TM plasmid 3 days before tumor cell inoculation (Supplementary Figure 1D), to ensure the presence of Env at the time point of tumor cell inoculation, i.e., when tumor antigens were introduced and presented to the immune system. The gene discussed is ERVW-1; the disease is neoplasm.