STAT3 and neoplasm: In addition, M2 macrophages also in the meanwhile, the tumour cells, activate the STAT3 transcription activator to stimulates tumour proliferation by secreting inflammatory factors such as IL-6,TNF-α, TGF-β, and fibroblast growth factor, as well as the degradation of extracellular matrix components, which facilitate tumour cell invasion and metastasis.