Also, the science behind carcinogen testing isn't exactly perfect. Ames testing (put cells on petri dishes, expose each dish to a varying degree of substance un

Also, the science behind carcinogen testing isn't exactly perfect. Ames testing (put cells on petri dishes, expose each dish to a varying degree of substance under test, plot results), for example, is subject to all sorts of problems related to the many, many ex-vivo variables those cells are exposed to simultaneously.