A notable, yet concerning attribute of embryonic stem cells is their ability to form rare, noncancerous tumors called teratomas. Teratomas differentiate similarly to embryonic stem cells, because the cells grow rapidly (Andrews 231). These tumors then form into a myriad of somatic tissues, such as: nerves, bones, muscles, or even hair (Thomson 233). This means if a stem cell transplant leads to the formation of teratomas, the patient would have one of these tissues growing in their body, causing further complications. Since teratomas are foreign to the body, the immune system responds by attacking the forming tissues. However, because the tissues are nearly indistinguishable from other tissues in the human body, the immune system will also attack healthy tissues of similar structure, leading to life threatening complications (Thomson 233). Furthermore, this is also a current problem for researchers because it is extremely difficult to accurately identify whether a cell is in fact a tumor causing stem cell or a healthy stem cell. In an…show more content… It is crucial, yet challenging for researchers to find genetically similar stem cells extracted from IVF spare embryos. Since IVF embryos are not always compatible with a stem cell patient’s genes, researchers are leaning towards therapeutic cloning; also known as Somatic Cell Nuclear Transfer (SCNT). SCNT is the process of extracting an egg nucleus and inserting the nucleus of somatic cells from a patient that requires a stem cell transplant (Murnagham). The egg is then stimulated and undergoes cell division to form a blastocyst. The somatic cells of the patient allow the egg to contain identical genetic information, thus stopping the issue of the body rejecting the stem cell
