Can a mark from a
Battlemind, etc. be maintained when the target goes invisible?
An attacker takes a -5 penalty to attacks against an invisible target. Invisibility has no special effect on marking, just that if the marking attack requires a hit it would be harder to achieve.
Turning invisible while marked does not remove it from you. Marks last either until the specified duration on the effect or until the marked target dies or falls unconscious.