Some people were asking about how to send a letter to the TSC to ask for expedite case processing. Actually there are forms for each center to do that. Here is the link to the form used by TSC: http://uscis.gov/graphics/formsfee/forms/files/g-731t.pdf
If your FP is going to expire, you can use this form to send request. Good luck all!
If your FP is going to expire, you can use this form to send request. Good luck all!