Talk:Ghoul/@comment-26306690-20151029005051/@comment-186.18.2.59-20151203220102

I think that some mutation at some point caused some humans to increase the amount of RC cells in their bodies. After several generations, they eventually developed an additional organ to control the excess of RC cells, which would be the kakuhou. Some bloodlines didn't get a particularly large increase in RC cells, but still got some; these would be those with super-strength and ROS patients. And other bloodlines were unaffected by this mutation.