Fig. 1.

Decision tree for calculation of input probabilities from inhibitor experiments. Calculated probabilities for each protein kinase (black box) take into account prior knowledge of the kinases that a given inhibitor can inhibit [downloaded from the International Centre for Kinase Profiling (ICKP; http://www.kinase-screen.mrc.ac.uk/)] and the results of immunoblotting to determine the effect of the inhibitor on aquaporin-2 (AQP2) phosphorylation at Ser²⁵⁶ (see methods for values of P₁ and P₂).