What is generally the upper age limit for receiving an allogeneic stem cell transplant?

What is generally the upper age limit for receiving an allogeneic stem cell transplant? So you know, more and more, allogeneic transplantation is feasible in patients. When I first started as a leukemia physician, we would say up to age 60, maybe, and even there it would be considered incredibly risky. Now we can routinely do allogeneic transplants up to age 75, and that's because the techniques in transplantation have really been refined so we can give less intensive chemotherapy before the transplant and really capitalize upon the immune effects of the allogeneic transplant to kill any residual cells. In fact, I kind of think of allogeneic transplant as the ultimate immunotherapy, another buzzword that we hear on TV all the time. But imagine you're replacing somebody's old immune system that can't kill their leukemia cells with somebody else's that now can actually recognize and destroy any remaining leukemia cells in the body after having had prior chemotherapy. So we can do this routinely up to around age 75 now. The other important point is that the technology of transplant is advanced so that when, again, looking back 15 or 20 years, generally speaking, transplants could only be done from matched siblings, matched family members, or a matched unrelated donor. Well now we can safely do transplants using cord blood, which is very rich in stem cells and it doesn't have to be a, so to quote, perfect match. Similarly, we can do haploidentical or half-matched transplants. So that means that a son can donate to his mother, right, or vice versa. So this opens up the opportunity for more patients to undergo transplant. So it is becoming a more common modality, particularly for those patients who have the poor risk chromosome and genetic abnormalities where we know that traditional chemotherapy alone is not going to offer a good chance of a cure.