Additional studies established the expressional change of 9,340 genes linked to itching associated with TRPA1 in skin biopsies from AEW-treated mice, showing that TRPA1 up-regulated the expression of 79% of itch-related genes known to be involved in the initiation and maintenance of chronic itching as well as pruriginous skin disorders (e.g., the IL-31 receptor (IL-31RA), aquaporin 3, and IL-33 (Wilson et al., 2013a; Nakahigashi et al., 2011; Nobbe et al., 2012; Olsson et al., 2006; Sonkoly et al., 2006). This evidence concerns the gene TRPA1 and skin disorder.