Related by context. Frequent words. (Click for all words.) 47 stem cell 47 stem cells 43 Stem cell 43 embryonic stem cells 43 unused embryos 42 embryonic cells 41 adult stem cells 41 cloned embryo 41 adult stem cell 41 stem cell research 40 unfertilized egg 40 Adult stem cells 40 cell transplantation 40 embryonic stem cell 39 stem cells derived 39 bone marrow stem cells 39 embryos 39 leftover embryos 39 fetal tissue 39 Embryonic stem cell 39 stem cell therapy 38 Eggan 38 reproductive endocrinologist 38 stem cell therapies 38 transplantation 38 embryo 38 Stem cells 38 cloned embryos 38 cryonics 37 somatic cell 37 fertility clinic 37 human embryos 37 cloning 37 Bone marrow 37 stem cell biology 37 Tissue Engineering 37 transplanted 37 Transplanting 36 umbilical cord blood 36 bone marrow stem cell 36 embryologist 36 transplant 36 Cord blood 36 SCNT 35 regrowing 35 fertilized embryos 35 bone marrow 35 regenerative therapies 35 gametes 35 Stem Cell Research 35 frozen embryo 35 transplanting 35 transgenic animal 35 biomedical research 35 transplanted tissue 35 Cryo Cell 35 regrow 35 Genetic Savings 35 islet cells 35 vitro fertilization clinics 35 Stem Cells 35 fertility clinics 35 ASRM 35 embryonic 34 Embryonic stem cells 34 stem cell transplants 34 regenerative medicine 34 destroying embryos 34 Vet Stem 34 Genetically engineered 34 Stem Cell 34 iPS cells 34 cord blood 34 therapeutic cloning 34 fertilized egg 34 ethically acceptable 34 Fertility 34 somatic cell nuclear 34 bone marrow derived 33 transplants 33 induced pluripotent stem iPS 33 cloned 33 Transplanted 33 marrow transplant 33 oocyte 33 Genetic testing 33 pluripotent stem cells 33 organ transplantation 33 curing diseases 33 insulin producing 33 hESCs 33 Transplantation 33 frozen embryos 33 pancreatic cells 33 Nature Biotechnology 32 blastocysts 32 extracted stem cells 32 diseased 32 Cloning 32 human cloning 32 ovarian tissue