IL2 and neoplasm: In another study, administration of AEPA-AEPD could significantly enhance the proliferation of splenocytes, increase the activity of natural killer (NK) cells, stimulate the secretion of interleukin-2 by splenocytes and upregulate the level of tumor antigen-specific antibody in the serum of tumor-bearing mice, which suggested that the anti-tumor activity of AEPA-AEPD was realized by enhancing immune response (Xu et al., 2009a).