As proven by the experiments by Wu et al., the activation of STAT3 signaling by IL-6 and IL-8 secretion led to the downregulation of receptors (NK protein 30 (NKp30) and NK group 2D (NKG2D) receptors) on the surface of activated NK cells, thus leading to impaired NK cell function and ultimately resulting in the development of esophageal squamous cell carcinoma [189]. Here, STAT3 is linked to esophageal squamous cell carcinoma.