I am Helen Blau, a Professor and Director of the Baxter Laboratory for Stem Cell Biology at Stanford and David worked in my lab for the past 12 years.

I am heartbroken that David is no longer with us, and my heart and the hearts of entire lab, many of whom are here today, go out to David’s mother, Pat, his sister and brother, his wife Chrissy and their 3 wonderful boys, John, Joe, and Ben.

David was an extraordinary scientist and a wonderful human being.  He was a star at U. Mass Med School where he received his Ph.D and the outpouring  of sympathy from the faculty there, including his advisor Joel Richter, and Nobel Laureate Craig Mello attests to that.  I have also received innumerable letters from colleagues at Stanford expressing their shock and dismay at his untimely loss.

David was an exceptional scientist. Soon after joining our lab, David was awarded one of the most prestigious postdoctoral fellowships in the world from the Life Sciences Research Foundation (LSRF). He was a fountain of knowledge, about science and about scientists.  He read incessantly.  He was a true scholar.

His scientific work was cutting edge.  He contributed to our understanding of how the expression of genes is controlled.  Your genes are really important as they determine how tall  you are, your hair color, how high you can jump.   DNA demethylation is an important epigenetic mechanism that controls the expression of your genes. David changed the way scientists view this mechanism, a crucial step in determining cell state…. or the conversion of one cell state to another.  For example nuclear reprogramming - we can now convert a specialized cell type like a skin cell or a blood cell to a cell that is similar to a cell from an embryo that has the potential to become any cell type.  This switch in cell fates requires DNA demethylation.  Many scientists believed this occurs by a passive mechanism in nuclear reprogramming, but David proved that it is due to an active mechanism, entailing base excision repair.  His work overturned the dogma in the field.

David shared his scientific thinking and accomplishments at international meetings.  I know that such trips were hard on Chrissy and the boys and he kept them to a minimum.  He was very proud of his children and he often talked of their achievements and how exceptionally smart they are.  But the meetings he did attend  were very meaningful to David.  I want you to know that his discoveries  were highly regarded by the scientific community and he got a lot of very positive feedback at these meetings. He championed his mechanism for driving changes in DNA methylation and changes in cell fates. He also had fun - One meeting he particularly enjoyed was at a stately home, Heston House in Sussex England, where he savored scones and clotted cream and indulged in the very British game of croquet on the lawn watching Sir John Gurdon, a scientist knighted by the Queen of England and a Nobel Laureate, angle his mallet with great determination.  I admired how forcefully and expertly he presented and defended our work, which was not always easy.

Indeed, David’s views and breakthrough science were highly regarded.  In 2011 soon after joining the lab we published a piece in one of the top journals CELL on DNA demethylation dynamics.  Two others followed shortly. Three more outstanding papers were in the final stages of preparation. The lab has rallied and we plan to publish the 3 papers he was on the verge of completing.  One proved his DNA demethylation mechanism.  A second showed how muscle stem cells from aged mouse muscles can be rejuvenated.  A third David liked to refer to as “inflammatory memories” – which was about the positive impact of an inflammatory metabolite Prostaglandin E2 –which even after a fleeting exposure, left a longterm imprint on the stem cells that was propagated to their progeny – their stem cell children and stem cell grandchildren.   Like the mechanism he studied, even an all too short exposure to David, will have lasting effects on all who knew him.

I miss David terribly. There is a huge hole in the lab.  Walking by his bench and his desk is a constant reminder.  There is a void. I know the lab members who are here today feel similarly. 12 years is a very long time.  We shared so much science and so many students and postdocs who came through my lab benefitted greatly from David’s wisdom and knowledge. He was a great mentor and teacher. I can’t believe he’s gone. Asuka has gathered photos and letters from members of the lab, past and present, and created a poster for the family which you can view here, which shows not only his serious side, but also his sense of humor.  Chrissy and the kids have visited the lab and we hope they will visit again to see where their father worked.

David was an intellectual, a scholar, a thinker, a friend.  He contributed so much to our lab and our lives working together.  Speaking  on behalf of the entire lab -- we deeply miss him and extend our heartfelt condolences to his family.