The Chimerism analysis shows that 99% of Mama Pham's cells are the donor cells! This is great news. It means that engraftment is happening (her body is taking the donated stem cells) and that the body is not making bad cells. Day 57 and going strong!I like the Seattle Cancer Care Alliance's description of the chimerism analysis:A Chimera was a creature in Greek mythology usually represented as a composite of a lion, goat, and serpent. Contemporary use of the term “chimerism” in hematopoietic cell transplant derives from this idea of a “mixed” entity, referring to someone who has received a transplant of genetically different tissue. A test for chimerism after a hematopoietic stem cell transplant involves identifying the genetic profiles of the recipient and of the donor and then evaluating the extent of mixture in the recipient’s blood, bone marrow, or other tissue.