The gene encoding cyclic AMP dependent transcription factor ATF3, decreased in both groups (Fig. 3A,B, Supplemental Table S6C), regulates cell proliferation and differentiation, and is a stress response gene that interacts with JUN and FOS; additionally, related genes, JUND and FOLSL1 are both downregulated in the keratoconus samples. Here, ATF3 is linked to keratoconus.