Two major results were generated from these papers: (1) the discovery of novel molecular alterations of the Notch signaling pathway in human HNSCC samples and (2) the validation of the PI3K pathway as one of the major targets for molecular alterations in human HNSCC samples, including alterations of the oncogene PIK3CA and the tumor suppressor gene PTEN. This evidence concerns the gene PIK3CD and head and neck squamous cell carcinoma.