To explain such a pro-inflammatory status in patients with KC, a compelling line of research is currently focusing on innate immunity hyperactivation: toll-like receptors 2 and 4 (TLR2 and TLR4) show increased expression both in conjunctival cells and monocytes/neutrophils of patients with KC compared to healthy individuals [92,93]. Here, TLR2 is linked to keratoconus.