To determine whether S. epidermidis affects cytokine mRNA expression in ACD, total RNA was extracted from the ear skin of each group, followed by RT-qPCR analysis to determine mRNA expression levels of Il-1β, Cxcl1, Cxcl2, Tnf-α, and Il-6 (Figure 4a–e, Supplementary Figure S1), which are known to be increased in ACD [14,15,16,17]. Here, TNF is linked to granular corneal dystrophy type II.