The present invention relates to a non-human animal model, cell and tissue
cultures derived therefrom, which do not produce or produce only
suboptimal levels of one or more functional sestrins and in addition do
not produce or do only produce suboptimal levels of latent transforming
growth factor .beta. binding protein 4 (ltbp4). Furthermore, the present
invention relates to a method for selecting agents for treating the
pulmonary emphysema and/or the colorectal cancer exhibited by utilizing
the animal model, cell or tissue culture of the invention. The animal
model, cell or tissue culture is suitable for preclinical testing of
efficacy, toxicity and bioavailability of potential agents.