Oral squamous cell carcinoma cell moving through a pore, coloured scanning electron micrograph (SEM). Oral squamous cell carcinoma is the most common type of mouth cancer comprising 9 out of 10 cases. Oral cancer is where a tumour forms and develops in the lining of the mouth. It my be found on the surface of the tongue, insides of the cheeks, roof of the mouth, the lips or the gums. Tumours may also develop in the salivary glands, tonsils or pharynx, although these are less common. The cell in this image is moving through a pore. This type of action may help scientists better understand how cancer cells are able to spread to other parts of the body in a process known as metastasis. Magnification: x7000 when printed at 10cm wide.