Head and neck squamous cell carcinoma (HNSCC) is the sixth most commonly diagnosed cancer worldwide, with an incidence of about 600,000 new cases per year, accounting for 1-2% of all cancer deaths worldwide. Current treatment for head and neck cancer includes taxol (docetaxel), platinum compounds (e.g. cisplatin or carboplatin) and the anti metabolite 5 fluorouracil (5 FU), either as single agents or in combination, and also radiotherapy. Response rates to these chemotherapeutic drugs range from 60 to 80%, however there are high rates of resistance, which often leads to locoregional recurrence and metastasis. The therapeutic dose of treatment needed (hormone therapy, radiotherapy or chemotherapy) is often too toxic for the patient to withstand. Therefore, our main objetive in this proyect is the identification of the molecular and cellular mechanisms involved in the acquisition of resistance to chemotherapy as currently key pieces for the discovery of new drugs that allow the development of effective therapies against HNSCC.