In this video we explain what cancer is and how it starts. Cancer begins in our cells. It happens when something goes wrong when cells are dividing. We explain how a tumour can develop and what might cause it. Visit our website: https://www.cancerresearchuk.org/abou... for more information about what how cancer develops.

For information about causes: https://www.cancerresearchuk.org/abou...

Information about a specific type of cancer: https://www.cancerresearchuk.org/abou...