Borrowing nature's blueprint: Scientists replicate bone marrow

This has the potential to be very helpful. Donating bone marrow or blood stem cells is uncomfortable* and requires taking time off which makes it difficult for people with job/family constraints. So a pool of potential donors are likely dissuaded from volunteering to donate.

*As a donor (stem cells; the easy one so I'm not a hero), it's not a pleasant experience, but I'm guessing it's way easier than dealing with the actual cancer, so have no grounds to complain.