Curse and mark of Cain

The curse of Cain and the mark of Cain are phrases that originated in the story of Cain and Abel in the Book of Genesis. In the stories, if someone harmed Cain, the damage would come back sevenfold. Some interpretations view this as a physical mark, whereas other interpretations see the "mark" as a sign, and not as a physical mark on Cain himself. The King James Version of the Bible reads "set a mark upon Cain".