Board Thread:General Discussion/@comment-1509585-20141214234153/@comment-996391-20141225100714

Coulson was dead but he came back. Coulson was resurrected with the serum made from Kree blood. The genes of Skye's mother's ancestors were altered by the Kree. Skye's mother became nearly immortal thanks to a Kree device. It's easy to assume that Skye's mother's blood had the same healing properties like the Kree blood.