Fresh leukapheresis product (LP) is a critical raw material in the global biopharmaceutical industry, being essential across many primary cell research and therapy development applications. Typical packs of LP comprise many billions of primary cells that closely reflect in vivo morphology, metabolism and growth. Kevin Bobofchak at Lonza Bioscience Solutions and Noor Mohammed at AllCells outline how this enables researchers to advance in vitro research into immune behaviour and function.