The use of stem cells to treat or prevent a disease or condition is known as stem-cell therapy. The development of various sources for stem cells, as well as the use of stem-cell therapy for neurological illnesses and conditions including diabetes and heart disease, is currently underway. Following breakthroughs such as scientists' capacity to collect and culture embryonic stem cells, produce stem cells utilising somatic cell nuclear transfer, and apply procedures to create induced pluripotent stem cells, stem-cell therapy has become contentious. Stem cell transplants are treatments that replace blood-forming stem cells in persons whose stem cells have been damaged by high-dose chemotherapy or radiation therapy used to treat certain cancers. Blood-forming stem cells are crucial because they differentiate into many types of blood cells.