Auxin regulation of different developmental processes. In Arabidopsis, six TIR1/AFB can interact with 23 different Aux/IAAs to form numerous coreceptor complexes. In addition, each Aux/IAA protein may interact with up to 19 ARFs to regulate distinct sets of target genes that control different physiological processes. (Reproduced from Salehin et al. [2015], Figure 2.)