Looks like although some disagree, most people have said micro has been a fairly significant part of Step I. Even if there weren't tons of straight micro questions, at least micro was a part of a large number of questions. I could have this wrong, but that's the impression I got from skimming posts. As for Immuno, I wasn't able to get a sense of how heavy that's been hit recently, so if anyone has any experiences, please chime in. Anyway, seems like most people recommend Micro Made Ridiculously Simple and the Levinson and Jawetz Immuno section. I have a few books, although not the Levinson/Jawetz book, and I'm trying to decide between which to read: Micro: Kaplan's lecture notes or MMRS (roughly similar length, Kaplan may be a little shorter) Immuno: High-Yield or Kaplan's lecture notes (Kaplan's is like 250 pages, while HY is only 70 pages) Any advice? TIA.