ACHP is an inhibitor of IκB kinase β (IKKβ) and IKKα (ICs = 8.5 and 250 nM, respectively). It is selective for IKKβ and IKKα over IKKγ, Syk, and MKK4 (ICs = >20 µM for all). It reduces the constitutive phosphorylation of IκBα and NF-κB p65 in U266 and NCU-MM-2 multiple myeloma cells when used at a concentration of 50 µM. ACHP (0.1 µM) prevents TNF-α-induced activation of NF-κB in U266 cells and inhibits the growth of U266, NCU-MM-2, and ILKM2 multiple myeloma and BJAB B cell lymphoma cells (ICs = 18.3, 27.6, 34.6, and 17.6 µM, respectively). It prevents HIV-1 replication induced by TNF-α in OM10.1 cells latently infected with HIV-1 (EC = 0.56 µM). Topical administration of ACHP (5 mg/kg) prevents skin inflammation induced by phorbol 12-myristate 13-acetate (PMA; ) or imiquimod and reduces cytokine and chemokine expression induced by imiquimod in mice. It also prevents skin erythema induced by UV light and reduces the incidence of tumors induced by 7,12-dimethyl benzanthracene by 50% in mice when administered topically at a dose of 5 mg/kg.