Blood cells are continuously produced from stem cells in the bone marrow. The use of blood cells as a source for generating iPS cells is gaining more widespread interest due to the ease in accessibility. Some popular blood cell types used are CD34+ progenitors, erythroid progenitors, T- and B-cells. However, T- and B-cells are less ideal target cells for reprogramming due to the TCR and IgG gene rearrangements, as these may affect the downstream function of iPS cells generated from them.