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现在有消息说克隆人可能比以前所认为的要容易。
Cloning1) Humans May Have It Easier
Most scientists agreed that cloning an entire human being －－besides being morally question－able －－was fraught with technical obstacles2)．After all，research into animal cloning has already shown that there are hundreds of failures，including many badly deformed3) creatures that were usually miscarried4)．
Now comes word that it might be easier to clone humans than was previously believed．People have a genetic quirk that might pr event some of the developmental deformities associated with animal cloning．One gene，called IGF2R，is normally imprinted5) in sheep，cows and mice but not in humans．Human clones would always inherit nonimprinted IGF2R genes，so t here would be no chance of a mix－up and，their growth would be normal．But what of the other 49or so imprinted genes？No one knows what trouble they might cause．So the fact that humans have one less imprinted gene than mice，sheep or cows means that human cloning might be marginally easier，but not necessarily safer．
