Texas A&M Health researchers have unveiled CODS, a caffeine-operated dissociation system designed to act as a molecular “pause button” for engineered cells. Published in the Journal of the American Chemical Society, the system uses AI-guided de novo protein design to rework a caffeine-responsive proximity module into a ligand-dependent dissociation mechanism. CODS pairs a caffeine-binding protein with a synthetic mini-binder built through a platform called BindCraft. Without caffeine, the complex stays locked; adding caffeine triggers dissociation and shuts down an attached cellular function. The team demonstrated CODS in multiple engineered contexts, including reducing transcription in gene circuits, controlling a rewired pyroptosis pathway via gasdermin D release, and—most translationally—dampening CAR T-cell activity without destroying the therapeutic cells. The work positions caffeine as a widely familiar, externally controllable trigger for reversible regulation in cell therapies, potentially improving safety by enabling temporal control over highly active immune cell programs.