Also, I just searched for "transgender" on nih.gov, and got lots of hits [2], the first one being a publication on PubMed [3].
[1] https://www.reddit.com/r/NIH/comments/1j28ytk/comment/mfs14d...
[2] https://search.nih.gov/search?utf8=%E2%9C%93&affiliate=nih&q...