You need to see what kind of fabric pens use used first. Some have to be erased. Some just disappear. Some have to be misted. Some have to be soaked. Don't press or apply heat until you know what you used because heat sets some marking permanently.
Hello, everyone, I used some kind of fabric pencil and other kinds of fabric mark pen to trace the quilt design on my quilt. Now I am pretty much done with the quilting. How do I get rid of the mark?
Some don't come out. 
