Moreover, as recently reported, simple structural modifications may easily convert a bona fide MDM2 PROTAC degrader into a molecular glue. The effects of protein-protein interaction in the ternary complex formation has been characterized by a cooperativity term. It is defined as the ratio of the dissociation constants for the interactions between the ligand and one of the two protein components in the absence and presence of the other. The cooperativity of a molecular glue system is physically determined by the complementary interface between the ligand and the dimerization partner as successfully estimated by crystal structure studies. Thus, for molecular glues, cooperativity is a key parameter describing the activity of the compounds, which informs the competence of a molecular glue compound. The first rational discovery of molecular glues between a ligase and a protein of interest involved a series of compounds that enhance the interaction between an oncogenic transcription factor, β-catenin, and its cognate E3 ligase, SCF β-TrCP. These compounds promote the ubiquitination of β-catenin by β- (FKBP12) protein degradation, etc. Recently, a new approach has been applied to a challenging target class -the intrinsically disordered proteins. It involves forcing disordered proteins to acquire a druggable interface using molecular glues to stabilize their interaction with 14-3-3 adaptor proteins, a signaling hub for critical cell processes. These examples demonstrate that molecular glues are emerging as a promising new therapeutic strategy.