We have previously shown that clearance of B16-TK tumours (B16 tumour cells engineered to express the Herpes Simplex Virus thymidine kinase gene) by ganciclovir (GCV) is dependent upon CD8+ T cells, and that tumour-cured mice have CD8+ T cell responses (Tumour Experienced (T.E.)CD8+ T cells) against multiple B16 tumour associated antigens (TAA) 56, 57, 58, 59 and Fig. 2F. This evidence concerns the gene TKT and neoplasm.