Colorectal cancer — cancer of the colon or rectum — is the third most commonly diagnosed cancer in the US. To reduce the chances of a diagnosis we are all urged to stop smoking, keep our weight down, decrease our intake of alcohol and red meat, keep active, and get screened for colon cancer. But, new research has found something that participates in the development of colorectal cancer that might not be as easy to control: A strep bacteria that promotes tumor growth.