Neutrophils and other cells secrete tumor growth promoting factors (VEGF, HGF, IL6, IL8, MMPs, elastanes) thus contributing to microenvironment of tumor stimulation (for example, IL6 has been shown to be at higher concentrations in 13 different types of neoplasia and associated with higher tumor stage and adverse prognosis). This evidence concerns the gene CXCL8 and neoplasm.