Somatic cloning in mammals became possible due to refinement of the nuclear transfer technique consisting of using nuclear donor cells in GO or activating reconstituted oocytes few hours after nuclear transfer (post-activation). Sheep, goats, pigs, cattle and mice have been cloned this way; the latter two species - of both sexes. Cloning of transgenic mammals producing human therapeutic proteins in milk (or urine) can find application in pharmacology and medicine. Somatic cloning of a goat producing human antithrombine III in its milk has already been achieved.