MSB Trading 2021 - paradigm shift, page-8152

It has been quite a while since I last read the Simmons patent, so I have to thank @medsci8 for leading me on a trip down memory lane!

One of the more interesting statements in that patent is as follows:

"It is anticipated that a proportion of the population purified will be stem cells, however, it is not yet known how to separate these stem cells from the MPC population. It has been observed however that a subpopulation has a much greater capacity to divide than others, and perhaps this subpopulation represents the stem cells. It is estimated that approximately 10 to 20% of the MPCs isolated by the illustrated method of this invention are stem cells."

So MPC's (ie Rexlemestrocel) were then thought to only contain small numbers of stem cells.

Of course, we now know (through the separate researches of Arnie Caplan and Paul Simmons) that they are not stem cells at all, and MSB no longer refers to them as such. That realisation was critical to the understanding of the role of MPC's in diseases such as GvHD, ARDS, diabetes, etc. and ultimately to inform the development of the CMC registration package.