Related by context. Frequent words. (Click for all words.) 80 embryos 78 embryo 76 embryonic stem cells 76 embryonic stem cell 73 human embryonic stem 71 therapeutic cloning 69 human cloning 65 stem cell research 65 stem cell 64 frozen embryos 64 adult stem cells 64 stem cells 61 cloning 60 adult stem cell 58 vitro fertilization 57 Stem cell 54 fertility clinics 54 fertilized egg 53 Cloning 53 IVF 53 Stem Cell Research 51 Embryonic stem cells 51 embryonic 51 fertility treatments 49 Stem Cell 49 iPS cells 48 genetic modification 48 abortions 47 Bioethics 47 umbilical cord blood 46 fertility clinic 46 cloned animals 46 abortion 46 stem cell therapy 46 fetuses 45 Stem cells 45 genetically modified crops 45 bioethics 45 genetically modified 44 artificial insemination 44 unborn 44 unborn babies 44 cloned 44 Advanced Cell 43 insulin producing 43 genetically engineered 43 regenerative medicine 42 Abortion 42 organ transplants 42 fetus 42 sperm 41 genetically altered 41 gene therapy 41 Stem Cells 41 sex marriages 41 biotech crops 41 Regenerative Medicine 41 contraception 41 surrogacy 41 eggs 40 GMOs 40 ethicists 40 comparative effectiveness 40 partial birth 40 bone marrow transplants 40 commercial whaling 40 assisted suicide 39 flu vaccines 39 euthanasia 39 vaccines 39 cluster munitions 39 sex marriage 39 synthetic biology 39 vitro 38 gay clergy 38 genetically modified foods 38 cord blood 38 biomedical research 38 Abortion opponents 38 Geron 38 vaccine 38 tissue 38 fertilization 38 bone marrow 37 fertilized 37 gay marriage 37 transplantation 37 ovaries 37 contraceptives 37 transgenic 37 unborn child 37 procreation 37 ovary 37 influenza vaccines 37 medical isotopes 36 Terri Schiavo 36 infertile 36 Fertility 36 flu vaccine 36 cellulosic ethanol 36 legalized abortion