CCL17 and dermatitis: The DNCB-only group exhibited significantly increased dermatitis scores, ear and epidermal thickness, and mast cell count (Figure 3 and Figure 4), with elevated mRNA levels of pro-inflammatory cytokines, including TNF-α and IL1β, as well as Th1-related cytokines like IFN-γ and Th2-related cytokines such as IL4, IL13, IL31, TSLP, TARC/CCL17, and MDC/CCL22 (Figure 5).