The problem of molecules interaction based on the spatial structure is central to many fields of biology. Methods of building libraries that contain vast numbers of different molecules offer new appro- ach in ligand-oriented research. One of these methods is phage display technology using libraries of peptides displayed on filamentous phage particles. Among many applications of the technique, structural peptide mimicry seems to be particularly important, since it opens a possibility for cancer immunothera- py to utilise peptide epitopes instead of glycolipid ones. The search for peptide sequences that mimic GD2 ganglioside present on neuroblastoma cancer cells comes as an example of this strategy.