Interestingly, loss of function of NOTCH1 suppressed the expression of HER3 but boosted the phosphorylation of AKT serine 473 (S473) in SCCHN cells, suggesting that NOTCH1 affects the PI3K/AKT pathway more profoundly and independently of its effects on HER3. This evidence concerns the gene ERBB3 and head and neck squamous cell carcinoma.