Stem cells in the early embryo The embryonic stem cells, that develop into the new individual, reside in the so-called inner cell mass in a few-days old embryo, called a blastocyst. During the last 25 ...

sometimes called "pluripotential stem cells" (PSCs), are found in the inner cell mass of the preimplantation embryo and in certain cell populations of the early fetus. Stem-cell research took a ...