Figure shows the response of ternary-complex concentration [ALB] as a function of [L tot ] with varying cooperativities and binary binding affinities according to Eqs. ( ) and . In the case of non-cooperative strong binding (α=1 and K A-L =K B-L =0.2µM, the grey line in the left panel of Figure ), a high concentration of [L tot ] can lead to a strong hook effect (or the prozone phenomenon) . This means that a decrease in [ALB] occurs with increasing [L tot ] because of saturated binary concentrations [AL] and [BL], which is often observed in bifunctional PPI stabilizers . The hook effect is mitigated when cooperativity increases (yellow and blue lines) or binding affinities decrease (middle and right panels of Figure ). The optimal ternary-complex concentration [ALB] opt occurs at an optimal total ligand concentration [L tot ] opt with a corresponding monomer concentration [L] opt (see Section S1 in the Supporting Information for the derivation),