The mean difference between two KCs thus increases to 100–160 PNs during odor; if the fan-in were 100 PNs per KC (c = 0.125), or 10 PNs per KC (c = 0.0125), the mean difference would become 44–70 PNs, or 5–8 PNs, respectively. The gene discussed is TBCE; the disease is keratoconus.