Nickel-induced down-regulation of ΔNp63 and its role in the proliferation of keratinocytes

► Ni suppressed ΔNp63 expression in HaCat cells. ► Ni activated NF-κB, decreased expressions of IRF3 and IRF7, IKKε, and Sp100. ► Over-expression of IRF3 increased ΔNp63 expression suppressed by Ni. ► Ni activated p21, and its activation was offset by over-expression of ΔNp63. ► Elevated p63 expression counteracted the ability of nickel to restrict cell growth.