IL2 and neoplasm: Deploying the biauricular VX2 rabbit model that is characterized by the installation of one VX2 tumor in each ear, an immunological approach in which interleukin-2 (IL-2) was applied peritumorally around a solid tumor showed high remission rates of the tumors, which also included the contralateral tumors not treated locally with IL-2, as well as existing lymph node metastases [109,110].