Neurons from stem cells, fluorescence light micrograph. Stem cells are able to differentiate into the many cell types in the human body. The type of cell they mature into depends upon the biochemical signals received. In this case, they have matured into neurons (nerve cells). They were derived from induced pluripotent stem cells (iPSC). These cells have been stained for beta III tubulin (green) and DAPI (blue). Beta-tubulin is a form of the cytoskeletal protein tubulin. DAPI is used to stain cell nuclei. This culture is from human tissue.