To find these "potent responders," tests for mean response greater than the detection limit of the assay are performed using weighted t-tests with the same weighting scheme used for WNLS [see Supplemental Material, p.
Compounds with significant fits to the Hill model using either NIS or WNLS, but not both, are classified as INCONCLUSIVE* [[+ or -]3].
* Fit the four-parameter Hill model better than a horizontal line (no response) in either the unweighted (NLS) or weighted (WNLS) curve fit.