<p>Hello,
I noticed that apart from the optional letter of rec on the main MIT portal, there is a separate "references" section in Slideroom where you submit your research paper. Does admissions see this letter also? Should I not put my mentor as an optional letter if she's already submitting to the Slideroom references section?</p>
<p>Correct – if you submit a letter from your research mentor in the research supplement, you don’t need to submit one as an optional reference, because they’ll see the research supplement.</p>