Understanding how a drug will function in an individual patient is challenging. The available amount of a drug’s molecular target may vary from patient to patient, the drug may bind its target differently in each patient, and individual patients could respond uniquely to drug-target recognition. This variability makes developing drugs and choosing treatments for specific patients unpredictable. There are currently no optimal model systems to address this issue. Dr. Summer Gibbs of Oregon Health & Science University is working collaboratively with teams from Dartmouth College and the Illinois Institute of Technology to develop a system that will predict a therapy’s effectiveness and uncover potential toxic side effects. This method, called intracellular paired agent imaging (iPAI), makes use of fluorescently labelled molecules to quantify the presence of intracellular drug targets, drug accumulation, and protein signaling in tissues derived directly from the patient. iPAI will provide information on drug behavior simultaneously across a pathway, link target binding with pharmacokinetic response, and ultimately predict an individual’s therapeutic outcomes. When used in the clinic, iPAI could improve cancer therapy selection and provide better understanding of resistance to treatment.