Nearly every cell in a person's body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA)
All your cells contains the same genes, but cells don’t make all the proteins the have genes for. What makes a liver cell different from a brain cell is which proteins it makes and therefore, which of its genes are turned on.
