Moderately immunogenic HPV 16-associated tumours TC-1 (MHC class I + , HPV 16 E6/E7 + , G12V Ha-ras + ) and MK16/1/III ABC (MHC class I - , HPV 16 E6/E7 + , G12V Ha-ras + ), both of the H-2 b haplotype and transplanted in syngeneic mice, were used to examine the adjuvant effects of IL-2 and dendritic cells for surgical therapy. Mice were inoculated s.c. with the respective tumour cells, and when the tumours reached 8-12mm in diameter, they were extirpated. Three days after surgery, the experimental mice were treated with IL-2, IL-2 gene-modified tumour vaccines, or dendritic cells, injected s.c. to the site of previous surgery. It has been found in both, MHC class I + and MHC class I - tumours that the recombinant IL-2 and IL-2 gene-modified vaccines substantially reduced the tumour recurrence rate and inhibited growth of tumour recurrences. The dendritic cells were significantly effective only in mice with surgical minimal residual TC-1 (MHC class I + ) tumour disease and when injected before they have reached the terminal stage of their differentiation.