So much depends on the situation. Earlier today I folded them preflop when a player to my right, who I knew to be tight, came in for 5 BBs. Sure enough, he turned out to have pocket Kings, and the guy who called wound up losing half his stack.
If it had come round to me unraised, I`d have probably raised myself, because this table was pretty passive and I`d have had a reasonable chance of buying the pot with a continuation bet even if I missed the flop.
At a more aggressive table, I`d limp in hoping to hit a set. At this kind of table, a hidden hand like that can be gold dust because there will often be another player who will bet it for you and help you clean up.