STAT3 and squamous cell carcinoma: For example, it has been shown that an increase in desmoglein-2 expression is associated with an increase in the aggressiveness of epithelial tumors by PI3K/Akt, MAPK, STAT3 and NFκB pathway activation (in skin carcinomas) [42]; by EGFR upregulation, triggering lymphoangiogenesis, activating the MAPK pathway (in cervical cancer) [43,44]; by the formation of vasculogenic mimicry (in melanoma) [45]; and by the triggering of paracrine signaling through extracellular vesicles (squamous cell carcinoma) [46].