Stat3 as Oncogene (IMAGE) Harvard Medical School Caption When EGFR -- a cell-surface receptor --mutates in glioblastoma, the Stat3 protein becomes oncogenic and promotes tumor growth. The image on the left shows EGFR-mutated cancerous tissue in which Stat3 is active and thus advancing tumor activity. The right-hand image shows the same tissue without Stat3 activity, resulting in a healthier sample. Credit Harvard Medical School 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.