Because the proteins surrounding elephant ova are similar to those from pigs, these antibodies attack the elephant ova, too.

ECONOMIST: Elementary elephant control

He was able to obtain a supply to test on his son, though first he took the ova himself to make sure they were safe.

WSJ: In a Squeaky-Clean World, a Worm Might Help Fight Disease

But he also tried to shift blame for the fabrication to junior researchers who are associated with the hospital that provided human ova for his testing.

NPR: Author of Debunked Stem-Cell Papers Apologizes