Protein that can reproduce telomere (enzyme) in cancer cells. Cancer accounts for nearly one-quarter of deaths in the us, exceeded only by heart disease. Over 75% of all cases occur after age 55 (cause about 1500/day in north america) More in men = behavioral cause (lifestyle disease) (w): lung cancer most common, breast cancer unchanged (1930-1990) and decreasing. Caused by controllable factors (tobacco, diet/obesity, alcohol, lack of exercise) Hela cells (immortal cells) from henrietta lacks (1951) Most common human cells on the planet tumor cells preserved from her (easy to grow cancer cells inside human body, hard to grow outside: her cells in a way are immortal. Requires 8 to 10 mutations in the same cell (mutations happen continuously) Every cancer is different: every tissue can spawn (more than 100 forms, each tumor is unique will never be a cure) Unique to person and to the organ.