SNAI2 and head and neck squamous cell carcinoma: Both canonical and non-canonical WNT pathways in the tumor microenvironment contribute to EMT, metastasis and cancer stem cell maintenance in lung, colorectal and breast cancers [127].• The WNT pathway acts as a driver of bone metastatic invasion of prostate cancer [128].• The canonical WNT/β-catenin/Slug pathway contributes to cancer cell invasion and lymph-node metastasis of HNSCC [129].• Autocrine WNT7b plays a role in CRC metastasis by promoting EMT through the WNT/β-catenin signaling pathway [130].