But instead, minutes after TGN1412 was given to healthy young men, all hell broke loose. It turned out macaques, the animals used to test the drug in animal models, happen to have way fewer CD28 molecules on their T Cells than humans and so they reacted way less strongly to the drug than expected, creating a false sense of security. Also, for some reason the drug was administered ten times faster to the human volunteers than it had been in the animal model.*
