WNT5A and nasopharyngeal carcinoma: Secreted proteins, such as transforming growth factor-β (TGFβ), Wnt family member 5A (Wnt5A) and epidermal growth factor (EGF), are dysregulated in the microenvironment of NPC and promote the growth, epithelial–mesenchymal transition (EMT) and metastasis of NPC in an autocrine or paracrine manner [16–18].