After macrophages are recruited to the tumor area, several intracellular signaling pathways, such as the hypoxia inducible factor (HIF) pathway, the vascular endothelial growth factor (VEGF) pathway, and the nuclear transcription factor (NF-κB) pathway, are activated in the hypoxic microenvironment, leading to the accumulation of VEGF and eosinophil chemokines (Eotaxin) in tumor tissue that causes M2 polarization (91). Here, VEGFA is linked to neoplasm.