Skin Cell Tumors (IMAGE) Massachusetts General Hospital Caption Early skin cancer that is colonized with a commensal papillomavirus looks like a wart to the immune system and is effectively eliminated. Keratin 6+ hyperplastic epidermis (red) and Ki67+ proliferative cells (green) mark a wart-like skin tumor. Cell nuclei are seen in blue. Credit Jon Messerschmidt Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.