No more cell lines please

With recent concerns on the effects of lipophilic chemicals or hormones on human health, the establishment of various nuclear receptor-based evaluation methods to assess endocrine disrupting potential is required. Among these methods, mammalian cell reporter gene assays have shown high popularity as lipophilic chemicals are sensed, evaluated, and analyzed directly through a reporter gene within a whole cell. You can find hundreds of reviews like that:

Recent work from the XXX group has established a novel stable reporter cell line via site-specific genomic recombination by integrating a xxxx NR gene, its xxx response element and a luciferase reporter gene into the genome of a host HeLa cell line. The reporter cell established showed high sensitivity, selectivity, stability, and specificity against receptor specific lipophilic chemicals.
Unfortunately, it has been shown that each mammalian cell responds to NR activation in a different fashion, the reasons of such variability are due to different tissue expression of coregolators, adaptor molecules that couple NR to activating or repressive transcriptional machinery. The need is not for new cancer cell lines like HeLa, MCF7 or what else, in particular when engineered to express doubtful physiologic levels of receptors.

The need is for systems able to discriminate in vivo (and possibly in each tissue) activities of multiple nuclear receptors (or even multiple transcription factors) at physiological levels (and possibly without invasiveness).