I wouldn't say that. In their entire run. The show didn't have any plots doing with aliens and mutants. I doubt Mulder and Schully, would look into water powered cars, arrested kiddie show hosts, senoir citizen Nazi spys, and such like that.
Even when skinner came over. He was doing hard police work.
I would describe it was a bunch of truth seekers exposing dark conspirisies in a humorous manner. I would even call the show a Dramady.