Given our previous findings that PQA-18 suppresses inflammatory cytokine production through inhibition of PAK2 in T cells and does not cause side effects such as renal damage, liver damage or tumor formation even with long-term systemic administration in mice [21], PQA-18 is considered to be a lead compound for the development of a useful therapeutic drug targeting both inflammation and pruritus for AD. This evidence concerns the gene PAK2 and neoplasm.