This redox-sensitive transcription factor is well knownfor its protective role in oxidant- and particle-induced lung disease,s50 and its activation in cells has been promotedas a sensitive marker of the toxicity of ultrafine PM.51 All of the particles induced Nrf2 translocation,but CNP–Cu-treated cells showed a stronger effect than treatmentwith CNP and CNP–Fe, especially in the RLE cells. Here, CNP is linked to lung disorder.