6-Aminochrysene is an inhibitor of the growth of several solid experimental tumours in vivo and has a cancerostatic effect on human breast cancer[1]. Long term topical skin application of 6-Aminochrysene to mice induces development of benign skin tumors after 3 months and of skin malignancies after 7 months. Female mice respond earlier than males. Induction of skin tumors is more rapid when 6-Aminochrysene is applied ventrally instead of dorsally. Urinary excretion is about twice as high after skin application than after oral administration[2].