In my experience , the pathogenesis of diseases is heavily tested. they don't mention the name of the disease directly, they describe it's pathogenesis.
The stuff that felt like Step I material was mostly pathophysiology and a few genetic defects which you should have had hammered in by now. All the defects could be found in the Step II review books or UWorld. I don't recall any crazy biochem questions.
Definitely nothing to freak out about. I wouldn't break out the Step I study material to try to cover the stuff.