Some of the stress response transcription factor pathways with homologs in N. vectensis. Hypoxia activates both the HIF1α and MTF1 pathway, metal stress activates MTF1, oxidative stress activates the NRF2 pathway (as well as others, not shown), and organic xenobiotics activate AHR or various NRs. These transcription factors have specific response elements (REs) in the regulatory regions of responsive genes, including hypoxida RE (HRE; HIF1α/ARNT), metal RE (MRE; MTF1), antioxidant RE (ARE; NRF2), xenobiotic RE (XRE; AHR/ARNT), and specific NR-REs (e.g. estrogen response elements).