IL2 and neoplasm: There have been attempts to deliver interleukin-2 (IL-2) [11,12], interleukin-4 (IL-4) receptors [13,14], interleukin-12 (IL-12) [15], interleukin-13 (IL-13) receptor protein [16], transferring-diphtheria toxin [17], tumor growth factor-gamma, and tumor-specific cytotoxic T lymphocytes (CTLs) [18].