Stem cells are special cells that play an important role in the development of the human body. Some types of stem cells can be grown in a laboratory to create tissue that may help people with specific diseases. Whether that is a good option, depends on the origin of the stem cells.
For instance, if these cells are obtained from the umbilical cord, that is fine: this procedure does not harm a human being. But an embryo, a tiny human being, must never be used for this purpose. However, there is no principal objection to genetically engineered crops and animals, as long as this is done with respect and serves people.
