Is an embryo a human person? Pro-life supporters generally believe that a human person comes into existence at conception. Some believe that somatic cell nuclear transfer is sufficiently similar to normal conception with an egg and spermatozoa that a human person also comes into existence during therapeutic cloning. The process of extracting stem cells involves killing the embryo. To many pro-lifers, this is murder. They feel that murdering one person, the embryo, to cure another person of paralysis, or diabetes, or heart disease, etc. can never be justified. More details. Therapeutic cloning research may well be limited to those countries, like China, the UK, and perhaps Canada, where pro-life supporters are relatively few in number.