Neural stem cells, fluorescence light micrograph. These neural stem cells are derived from induced pluripotent stem cells (iPSC). They have been stained for the neural stem cell-specific intermediate filament protein nestin (green) and stem cell pluripotency-maintaining transcription factor SOX2 (red). Overlap of these areas produces a purple colour. 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. This culture is from human tissue.