On the other hand, a wide range of pro-inflammatory factors, e.g., PGE2, TNF, IL-1β, IL-6, S100A8, S100A9, IFNγ, IL-4, IL-10, and IL-13 secreted by cancer cells and leukocytes residing in the tumor inhibit the differentiation of myeloid progenitors and enhance their suppressive capacity (191). The gene discussed is S100A9; the disease is neoplasm.