**6. Conclusions**

Tier 1 *in vitro* assays are the front line in EDC detection. However, the limitations of traditional assay formats, which use non-human cell lines that can obscure bioavailability data [6, 7], require the use of radioactive materials that necessitate dedicated use areas and specially trained personnel [6–8], or rely on expensive analytical equipment [8, 9], are currently incapable of handling the sheer number of compounds that must be screened. Autobioluminescent assays, such as the HEK293-based estrogen-responsive bioreporter assay presented here, are uniquely positioned to overcome the limitations of existing assay formats by autonomously generating bioluminescence in response to target chemical or chemical class bioavailability. The use of these reporter systems allows bioluminescent responses to be linked to EDC detection for reagent-free, fully automated screening at a fraction of the cost of existing assays, providing a promising route toward addressing the existing EDC compound screening backlog.
