Imagine if the samples bring back some xenofungal spores. Spores are capable of existing in space's atmosphere (or lack there of). There was an unsubstantiated theory that all fungi came from outer-space and is possibly the progenitor for life itself. Fungi and all life have a rather close relationship. Such as what we see plants communication networks - - Also, the effect of chemicals like Psilosybin was also loosely attributed to the development of intelligence and the reason for humans to evolve (or transition) from being a creature of instincts to autonomous sentience.

So, would't it be cool is some new fungus arrive that creates an unforeseeable change; like super powers! Or perhaps extra dimensional perception.