Porcine endothelial cells, unlike human endothelial cells, can be killed by human CTL via Fas ligand and cannot be protected by Bcl-2.

Zheng L, Ben L-H, Pober JS, Bothwell ALM. "Porcine endothelial cells, unlike human endothelial cells, can be killed by human CTL via Fas ligand and cannot be protected by Bcl-2." J Immunol. 2002;169(12):6850-5.