Restoring tumor suppressor function in cancers harboring TP53 missense mutations has remained a major challenge in oncology. The TP53 Y220C mutation creates a mutation-specific surface pocket that destabilizes p53 folding, enabling a rational, structure-guided therapeutic strategy. Rezatapopt (PC14586) is a first-in-class small molecule designed to selectively bind this pocket, stabilize the Y220C-mutant p53 protein, and restore wild-type p53 structure and function. Here, we present insights from the discovery, biological characterization, and emerging translational evaluation of rezatapopt. Structure-based medicinal chemistry enabled progressive optimization of binding geometry, conformational stabilization, and pharmacokinetic properties, resulting in a clinical-stage compound that selectively reactivates Y220C-mutant p53 in tumor models, producing robust and sustained tumor growth inhibition. At the cellular level, p53 reactivation induced canonical p53 target genes while enforcing cell-cycle arrest through coordinated repression of DREAM- and E2F-regulated transcriptional programs, producing mutation-selective antiproliferative effects. We further demonstrate that pharmacologic p53 restoration reshapes cellular stress responses, creating context-dependent vulnerabilities that inform rational combination strategies. Data will be presented showing how p53 reactivation sensitizes Y220C-mutant tumors to targeted therapies, immunomodulatory agents, and stress-inducing treatments, identifying settings in which combination approaches outperform single-agent activity. The presentation will also address emerging translational and early clinical observations from ongoing studies of rezatapopt in patients with advanced TP53 Y220C–mutant solid tumors. Together, these findings support a model in which precise structural correction of mutant p53 re-engages endogenous tumor suppressor programs, creating new therapeutic opportunities across tumor types.