We received GC's in the mail last week but last night got a letter from USCIS requesting additional evidence for EAD which I forgot to have my wifes son sign his I-765 (sht !). Since we already have the GC, should I just ignore since it is worthless anyway and is probably automaticly cancled in the process? Or should I returned signed and state we already got the GC's with a copy of it for thier records? I think probably just ignore but what do you think??

thanks in advance for answers.

i would probably photocopy the rfe letter and write a note to say that you are abandoning the EAD as you have received your greencard...
At least they will know whats going on and close that file.

Thanks Kim & James.

That sounds like a good plan.