A multipeptide cancer vaccine targeting renal cell carcinoma with potential immunopotentiating activity. Renal cell carcinoma peptides vaccine IMA901 consists of 10 different synthetic tumor-associated peptide (TUMAP) antigens (9 HLA-class I-binding and 1 HLA class II-binding); endogenously, these TUMAPs are expressed by the majority of renal cell carcinomas. Vaccination with this agent may significantly increase host cytotoxic T-lymphocyte (CTL) immune responses against tumor cells expressing these peptide antigens.