Model for cell-adhesion–mediated cell-cycle arrest. Hypothetically ordered series of signaling events: cell-adhesion–dependent activation of APC/Cdh1 ubiquitin ligase complex, increased ubiquitination and degradation of Skp2, subsequent decreased ubiquitination and degradation of p27^Kip1, and ultimately p27^Kip1 accumulation, resulting in cell-cycle arrest.