Well, I took Step 1 last year and I was shocked to see just HOW LITTLE Path, Pharm, and Micro that I had on my exam. I had a ton of anatomy and embryology. Though I did okay, I probably would have done better if I had focused a little more on what I thought were lower yield subjects. Each version of the exam is different and most of my classmates did feel as if their exam was heavily Path-based. I must have been one of the unlucky ones!
Bottom line, anything can be asked! In all fairness, I might feel that way because embryo is a weak subject for me and I always tend to recall the questions that I had trouble with more so than the ones that I am sure of. Good luck to all who have yet to take Step 1!