LOXL2 and head and neck squamous cell carcinoma: Small extracellular vesicles (sEVs) derived from the hypoxic tumor microenvironment of head and neck squamous cell carcinoma (HNSCC) recruited MDSCs to form a premetastatic niche by delivering lysyl oxidase like 2 (LOXL2) to fibroblasts to induce fibronectin production (134).