The tumour microenvironment (TM), probably due to low oxygen pressure and the presence of tissue debris, attracts monocytes via chemokines CCL2, CCL5, vascular endothelial growth factor (VEGF), macrophage colony-stimulating factor (M-CSF), and TGFβ-activity, and generates changes in the population of these cells. The gene discussed is VEGFA; the disease is neoplasm.