Disclaimers
Assay/system dependence: If the system or assays change, the
same ligand and receptor may display a very different
pathway-preference. However, the same may actually be true even when
using a reference ligand, as that does not equate any imbalance in
pathways, but merely move the baseline. Imbalance in pathways is instead
predominantly determined by the choice of systems and assays, which
should be as similar as possible.
Fold potency: Fold potency comparisons without the inclusion of
efficacy are merely to be seen as a prediction of potential
pathway-preference or bias, as in case the efficacies were known, the
real relationships may be very different.