CD4 and neoplasm: We found that the extent of intratumoral diffusion of HCT-mono-mIL12 is strongly correlated with the numbers of CD4+ and CD8+ T cells and the cytotoxicity of CD8+ T cells as well as their even distribution in the TME, suggesting that sufficient presence of IL12 in the TME can induce the tumor infiltration of T cells (41) and/or stimulate the in situ proliferation and activation of preexisting T cells to kill tumor cells in the TME.