AREG and keratoconus: Given the decrease in percentage of cells observed in the limbal suprabasal cell cluster 4 in keratoconus patients (Fig. 7B), we performed a differential gene expression analysis for this cluster between the unaffected subject and keratoconus patients (Figure S20, Table S10), revealing a significant decrease in LPC (KRT14, KRT15, TXNIP) as well as a significant increase in expression of differentiated corneal epithelial cell markers (AREG, KRT3, HES1) in keratoconus samples.