However, although these findings suggest that sulforaphane protects against COPD and COPD exacerbation, the administration of sulforaphane to COPD patients unfortunately failed to induce Nrf2 target gene expression or affect the levels of other antioxidants or inflammation markers in a randomized, double-blind, placebo controlled trial in the US [121]. Here, NFE2L2 is linked to chronic obstructive pulmonary disease.