The primary objective is to establish an international anaplastic thyroid cancer tissue collection to facilitate research. Patients have the option to donate blood samples and clinical data. Research proposals will be accepted from academic and industry research parties from the UK and internationally. All research proposals will be submitted to the multidisciplinary iNATT Steering Committee for assessment. As the volume of tissue collected per patient is expected to be of small volume, by virtue of the specimen comprising core biopsy or fine needle aspirate material, research proposals will be prioritised according to the potential clinical benefits. Research proposals will require ethical approval and the relevant research and development permissions prior to commencement. ClinicalTrials.gov Identifier: NCT01774279