Lifestyle modification involves making long-term changes to habits like eating and physical activity to treat diseases. A lifestyle reflects one's attitudes, values, and world views. Diseases are the villains in the story, while heroes are positive lifestyle behaviors and emotions that alter brain chemistry and cell growth. Nurture, like lifestyle factors, can shape nature by inducing epigenetic changes that affect gene expression without altering DNA. Maintaining healthy cells through good circulation is important for overall health and preventing unhappy cells that can lead to disease. Lifestyle choices and environmental exposures are linked to various cancers and cancer mortality rates.