Researchers at the National Cancer Institute developed iDC1, a mouse bone marrow culture system that produces roughly 1.5 billion conventional type 1 dendritic cells from a single animal. The method uses a 23-day cytokine protocol coordinated around FLT3L, Kit ligand, and low-dose GM-CSF, with flow cytometry monitoring across multiple time points. The platform claims yield at least 75-fold higher than conventional recombinant cytokine approaches and maintains >95% CD103-positive cDC1 composition in final cultures. Mechanistic experiments separated early expansion and lineage restriction roles for the cytokines. For immunotherapy and vaccine developers, high-scale cDC1 production supports more robust preclinical testing, including antigen cross-presentation assays and combination regimen studies that require large cell numbers.