Oral administration of oligoderivatives of chitosan in mice with solid tumors of Sarcoma 180 [29] and by intravenous administration in mice with Meth-A tumor [30] induced tumor growth inhibition, increase levels of IL-1 and IL-2, and also a polarization to cytotoxic T lymphocytes, in the case of Meth-A. This evidence concerns the gene IL2 and neoplasm.