Cell interaction networks have been used for blood cells, development, and also stem cell biology - Morgan

There are low numbers of haematopoetic stem cells available. Growing stem cells is difficult, with at most 2-5 doublings. We know it's possible in vivo, but not yet in vitro. - Morgan

transplanting blood stem cells always results in less stem cells than normal, regardless of the number transplanted. Traditional argument is that there are limited niches for the stem cells, but they believe it has to do with feedback from more mature cells. - Morgan

Designing new, artificial niches for stem cells to grow in order to regulate their availability - Jochen Weile

"Model predicts competitive antagonism between primitive and mature cell output." - Morgan