What are different types of stem cells?

Different types of stem cells include: hematopoietic stem cells (HSCs), neural stem cells (NSCs), mesenchymal stem cells (MSCs), induced pluripotent stem cells (iPSCs), and human embryonic stem cells (hESCs). 

1. HSCs are precursor cells located in the bone marrow which can differentiate into various types of blood cells including white blood cells, red blood cells, and platelets; these cells are also able to self-replicate. 
2. Mesenchymal stem cells are multipotent cells located in bone marrow which are crucial for producing and repairing skeletal tissue including cartilage and bone, and the fat contained in bone marrow. During the process of aging, MSCs convert to lipid-accumulating fat cells and deplete in the bone marrow, which affects future bone growth. 
3. Neural stem cells are multipotent cells which can produce all the major cell types of the adult central nervous system. As examples, they are able to differentiate into astrocytes, neurons, and oligodendrocytes. 
4. iPSCs are a type of pluripotent stem cells which originate from adult somatic cells (e.g. skin or blood cells). Somatic cells are reprogrammed to induce iPSCs through the expression of transcription factors Sox2, Oct4, c-Myc, and Klf4. 
5. Human embryonic stem cells are pluripotent cells which produce all somatic cell types in the embryo. 
6. Embryonic stem cells are derived from 3-5 day old embryos that are in the blastocyst stage. More specifically, they are extracted from the inner cell mass of the blastocyst or fetal tissue.