Figure 1: Schematization of the four hierarchical levels of glycomics. The spheres represent the glycans. The deciphering of the purple sphere belongs to the first hierarchical level. The deciphering of the orange and purple sphere and the pinpoint of the point of interaction belong to the second hierarchical level. Organization into the space (3D) (long pink chains) resembles the third hierarchical level. On right a detail on mechanism of cell-cell interaction (forth hierarchical level).