However, anemia can also be caused during systemic inflammatory response to the tumor with higher concentrations of inflammatory cytokines such as interferon gamma (IFN-γ), different sorts of interleukins (IL-1, IL-6, IL-8 and IL-10) and tumor necrosis factor alpha (TNF-α) that directly or indirectly stimulate progression of anemia [3], [7]. This evidence concerns the gene IL6 and anemia (phenotype).