Surprisingly, we found no evidence for Nrf2 dependence of ACOX2 regulation in several human cell lines (i.e., HepG2 [hepatoma], Caco2 [colorectal cancer], and IMR90 [normal lung fibroblasts]) that we tested, and its expression levels were below the limit of detection in DLD1 (colorectal cancer), A549 (lung cancer), and U2OS (osteosarcoma) cells, indicating cell type and/or species specificity. This evidence concerns the gene NFE2L2 and colorectal cancer.