NFE2L2 and chronic obstructive pulmonary disease: A dysfunctional Nrf2 system (low levels, epigenetic changes and mutations) has been linked to elevated risk to develop both vascular diseases such as diabetes, cancer, COPD (regular and CS-induced) and chronic neurovascular diseases such as Parkinson’s disease (PD), Alzheimer’s disease (AD) and ALS [39, 42].