Talk:Saiko Yonebayashi/@comment-86.186.15.151-20150527140313/@comment-10733658-20150528065232

Actually, in that scene Kanou is wondering what other factors are involved. Blood type is one factor, but clearly that isn't the only one since out of his experiments only Kaneki and the twins were a success.

All things considered, all evidence suggests the kakuhou transplant follows the same rules as other organ transplants in terms of blood/tissue matching. So blood type is important, but obviously not the only thing determining whether someone is a success or a failure.

I suspect Yoshimura is probably Type O, which would make him a universal donor. At this point, we know he's either O or A since Takizawa was a success.....and either way, that gives the largest possible pool of candidates since A is the most common Japanese blood type.

And yes, there are hints that CCG was experimenting with hybridization in the past. Kuroiwa and Shinohara explicitly discuss it while Shinohara was in the hospital. Their superior told them a story about a doctor that was experimenting with it, but his research was shut down over "ethical concerns". Likely, Dr. Kanou picked up where that was left off.