NFE2L2 and cancer: There are several reports that NRF2 can either positively or negatively regulate CFTR expression, depending on whether the cells are under normoxic or hypoxic conditions, whether the cells studied are airway epithelial cells vs. intestinal epithelial cells (or renal cells), and whether the cells are normal vs. malignant, and possibly whether the malignant cells are early stage vs. late-stage cancer [125].