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). Here, MAPK1 is linked to melanoma.