Since loss of both cytotoxicity and cytokine secretion can be seen in NK cells in KC mice on HFCD, with the highest surface receptor expression for TLR4 (Figure 1A), it may be that the defect in NK function is not at the level of availability of TLRs on NK cells, but at the levels of ligand and/or post receptor signaling. The gene discussed is TLR4; the disease is keratoconus.