The present invention provides a compound represented by the formula (1):wherein Xa and Ya are each a single bond or the like, cancer antigen peptide A is an MHC class I-restricted cancer antigen peptide, and R1 is a hydrogen atom； a group represented by the formula (2):wherein Xb and Yb are each a single bond or the like, and cancer antigen peptide B is different from the cancer antigen peptide A and is an MHC class I or II-restricted cancer antigen peptide； a group represented by the formula (3):wherein Xc and Yc are each a single bond or the like, and cancer antigen peptide C is an MHC class II-restricted cancer antigen peptide； or cancer antigen peptide D, wherein the cancer antigen peptide D is an MHC class I or II-restricted cancer antigen peptide containing one cysteine residue, or a salt thereof, for example.
