Noun
the mark that God set upon Cain now refers to a person's sinful nature
Source: WordNetWith the whole Mark of Cain thing, does that mean if I accidentally kick you during the night, I get kicked in the shins seven times by an invisible force? Cassandra Clare
But to wield it, Dean had to take on the Mark of Cain. Source: Internet
The "Mark of Cain" storyline was revealed during the event in the Bat-titles and revealed Cassandra Cain's upbringing at the hands of the master assassin David Cain. Source: Internet
In the Bible it’s called the Mark of Cain. Source: Internet