I don't know anyone specifically out of my friends who tested out of histology. From what I remember it does not take up that much time during your first trimester and don't really think it interfered with me learning anatomy. With that being said, will you be at an advantage having tested out of it? I'm not really sure. You don't have to take histo during anatomy, but you still need to have it fresh in your head for the systems courses. We do still see slides and are responsible for them on tests beyond first semester when taking about dysplasia, staging malignancy, etc.... So you can't just forget it all if you test out of it, not saying that you will. I guess in the end its up to you, but it really is not the norm for people to go out of their way senior year to take histo so they can test out of it come med school, at pcom for my class atleast. Good luck with everything!!!