Someday soon, medicines might be commonly produced not in laboratories, but in barnyards and meadows! In this excerpt from her book Clone: The Road to Dolly and the Path Ahead, science writer Gina Kolata explains how cloned sheep could greatly expand the production of useful drugs: [Such sheep] might produce valuable drugs much more cheaply than did the methods used by drug companies[The researchers] would clone a lamb whose udder cells made the drug whenever they made milk-all they'd have to do is hook the drug-producing gene to the gene that is turned on when milk is produced and make clones from those genetically altered cells. Then the company could simply milk the sheep, extract the drug from the milk, and sell it. If the scientists made both male and female sheep that carried the added gene, they could breed these sheep and have a self- perpetuating flock of living drug factories.