Margaret: What is it?
Scully: It's the DNA test on Emily Sim's blood.
Bill: What does it say?
Scully: It says, definitely, that Melissa is not Emily's mother, but that they found striking genetic similarities between Emily and Melissa, so many that they ran a test against another sample that they already had.
Margaret: What sample?
Bill: What are you trying to say?
Scully: According to this... I am Emily's mother.