TCF4 and dry eye syndrome: Quantitative PCR (qPCR) analyses of skin demonstrated significant increases in Il17c (1.3-fold, P < 0.05) and a trend toward increases in Zc3h12a (1.2-fold, P > 0.05) expression in ears treated with si-Tcf4 versus si-control–treated skin (Figure 6E), confirming findings in human KCs (Figure 4B).