A method for the quantification of biased signalling at constitutively active receptors.

In systems with constitutive activity, the Slack and Hall model provides methods for quantifying the absolute bias of agonists and inverse agonists. This provides an alternative to methods based on RAi and is complementary to the ΔΔlog(τ/Ka ) method of Kenakin et al. in systems where use of that method is inappropriate due to the presence of constitutive activity.