A fine evaluation of the immune responses in these two patients [44] highlighted that peptide vaccination with a single mutant p21-ras-derived peptide induced CD4+ and CD8+ specific for nested epitopes, including the Gly/Val substitution at codon 12 and that both these T-cell subsets specifically recognize tumour cells owning to the corresponding K-ras mutation. The gene discussed is KRAS; the disease is neoplasm.