induced Pluripotent Stem cells from a 69 year old human: the hidden story?

The successful reprogramming (dedifferentiation) of differentiated human somatic cells into a pluripotent, embryonic stem cell-like state called induced pluripotent stem cells (iPS) using just 4 (and recently 3) introduced transcription factors is the biggest news of current stem cell biology. In the paper published in Cell by the Yamanaka group (Takahashi et al.) the iPS…

First differentiated cell types in mammals are…

…blood cells, “generated in early-stage embryos, for instance in mice in the yolk sac at embryonic day (E) 7.0.-7.5, just 2 or 3 days after the undifferentiated conceptus implants in the uterus.” Source: Ueno-Weissman: Blood lines from embryo to adult Nature 446, 996-997 (26 April 2007)