ITGA4 and plasma cell myeloma: This work presents (1) the development and characterization of both an immunocompetent isogenic model of mouse myeloma that ablates VLA4 function through CRISPR KO of its alpha subunit, Itga4, and (2) a novel tool to image activated VLA4 pre-clinically, ex-vivo, and in cells using a molecularly targeted, non-ionizing, near-infrared (NIR) imaging agent.