Injections of human stem cells seem to directly repair some of the damage caused by spinal cord injury, according to research that helped partially paralyzed mice walk again.
Mice aren't able to accept cells that aren't their own
( z1 possible :polarity - :ARG1 ( z2 accept :ARG0 ( z3 mouse ) :ARG1 ( z4 cell :poss z3 ) ) )