In genetics, somatic cell nuclear transfer is a technique for cloning.
As the donor cell is a somatic cell, it has to be artificially "activated" to start working as a fertilized egg cell, thus growing into a whole organism. The biochemistry involving this activation is far from understood.
Also, not all genetic information of the donor cell is transferred. DNA of organelles (mostly mitochondria) is not moved together with the nucleus, but remains that of the recipient cell. This procedure, as it is very ethical, has only been performed on mice.