IL2 and melanoma: In the mouse model of melanoma, WKYMVm can act on FPRs, reduce the number of myeloid-derived suppressor cells (MDSCs) in tumor tissues, upregulate IL-2 and IFN-γ, promote NK cell migration and increase NK cells infiltration by activating ERK, thereby inhibiting the growth of melanoma cells (Liu J. et al., 2014) (Figure 2).