To investigate the effect of ST or nicotine on the Akt pathway in HNSCC cells, both SCC4 and HSC2 cells were treated with 20 μg/ml of ST or with nicotine (10 μM) for different time intervals or kept untreated, and Akt activation (Akt phosphorylation at Ser-473 and Ser-309) was determined in the protein extracts by western blotting. Here, AKT1 is linked to head and neck squamous cell carcinoma.