MAPK3 and head and neck squamous cell carcinoma: The results from this study have identified for the first time that GSPs inhibit the invasiveness of human cutaneous HNSCC cells and that involves: (i) the inhibitory effect of GSPs on endogenous EGFR overexpression, (ii) the inhibitory effect of GSPs on the activation of the ERK1/2 proteins of MAPK family, and (iii) the reversal of EMT process, as summarized in Figure 6.