M1 subtype macrophages differentiate through mainly JAK1/2, STAT1/2, 5, TLR4/NF-κB, P38 MAPK pathway activation, excrete inflammatory cytokines and chemokines, participate in a positive immune response; as such, they are able to kill tumor cells in tumor tissue and foreign pathogens. This evidence concerns the gene NFKB1 and neoplasm.