In this study, we describe the structure-based developmentof thefirst fluorescent ligands targeting the intracellular allosteric bindingsite (IABS) of the CC chemokine receptor type 1 (CCR1), a G protein-coupledreceptor (GPCR) that has been pursued as a drug target in inflammationand immune diseases. The gene discussed is CCR1; the disease is immune system disorder.