I'd beg to differ. Day 1 is very heavy on Step 1. I'd estimate it was 30-40% of day 1. Lots of antimicrobial mechanism of action, a couple histology questions, chromosomes, cancer genetics, pedigrees, immunology, and pathophysiology. Biostats can be considered Step 1 material as well. I'd recommend reviewing some parts of the good old First Aid book.
Of course, this is only if you're concerned about getting at least an average score (227) or higher. If you're quite sure you can pass, don't worry about it too much.
Day 2 MCQs had no Step 1 material on it. More similar to Step 2 CK questions.