The CC6-469 monoclonal antibody specifically recognizes Leucine-rich repeat-containing protein 15 (LRRC15). LRRC15 is a single-pass type I transmembrane glycoprotein that is encoded by LRRC15 which belongs to the Leucine-rich repeat (LRR) domain superfamily. LRRC15 is a 581 amino acid protein with 15 extracellular LRRs, a transmembrane region, and a short intracellular tail. LRRC15 is expressed by stromal cells found in the placenta, skin, lymphoid tissues, and by activated fibroblasts in wounds. LRRC15 is also expressed on fibroblasts in solid tumors including those of the breast, lung, head and neck, and pancreas and on cancer cells of mesenchymal origin found in sarcomas, melanomas, and glioblastomas. LRRC15 is involved in cell-to-cell and cell-to-extracellular matrix (ECM) interactions. LRRC15 expression can be highly upregulated by cancer-associated fibroblasts (CAFs) in response to TGF-β that reside in the tumor microenvironment.