A common misconception is that the cells can come from aborted fetuses, which is in fact not possible. As a matter of fact, despite the amount of public attention they get, embryonic stem cells are among the smallest group of stem cells currently being researched. In the past few years a number of techniques for the derivation of pluripotent cells without the destruction of embryos have begun to emerge, and one in particular has made great strides: the development of so-called induced pluripotent stem (iPS) cells. These cells, first described in humans in November 2007, are produced by inserting certain stem-cell-associated genes into regular adult cells (like skin cells). The process transforms the adult cells into pluripotent stem cells, which seem to share the key characteristics of embryonic stem cells but do not require the creation, use, or destruction of a human embryo. So where do the rest of these stem cells come from? Stem cells can be found from a variety of sources including: bone marrow, placenta and cord tissue, amniotic fluid, teeth, umbilical cord blood. Adult stem cells have been found in the brain, bone marrow, blood vessels, skeletal muscle, skin, teeth, heart, gut, liver, and other organs and tissues.