However, at the delayed phase (24 h), CTH mRNA was upregulated in the TNCB-treated ears of WT and Mpst–/– mice, whereas MPST mRNA was downregulated in the TNCB-treated ears of WT and Cth–/– mice (Figure 5C,D), suggesting protective roles of CTH against the delayed phase of TNCB-induced contact dermatitis. Here, MPST is linked to contact dermatitis.