[ALL SPOILERS][EVERYTHING] Quick question. GRRM quote about Jon.

Hope someone can provide me with a link. I keep reading that GRRM has said in an interview that Jon will find out who his parents are. I can't find it anywhere. Only an interview where he says we'll find out who they are. Can anyone help me with this one? Obviously if GRRM did say it, it confirms that Jon isn't staying dead.