Environmental agents such as radiation and chemicals are known to cause genetic damage.
Alterations in a limited set of cellular genes called proto-oncogenes lead to unregulated
proliferation and differentiation. We have studied the role of the ras gene family in
carcinogenesis using two different animal models. In one case, thymic lymphomas were
induced in mice by either gamma or neutron radiation, and in the other, keratoacanthomas
were induced in rabbit skin with dimethylbezanthracene. Human keratoacanthomas similar …