CLEC9A encodes a C-type lectin receptor primarily expressed on CD141+ dendritic cells (DCs), which are equivalent to mouse cDC1 cells specialized for cross-presentation 1. The protein functions as a dedicated cross-presentation receptor that recognizes F-actin exposed in dead cell debris, facilitating uptake and processing of dead cell-associated antigens 23. Upon ligand binding, CLEC9A signals through SYK activation and NADPH oxidase to promote phagosomal rupture, allowing escape of contents into the cytosol where they access the MHC class I antigen processing pathway for cross-presentation to CD8+ T cells 3. This mechanism is critical for anti-viral and anti-tumor immunity, as CLEC9A+ DCs are essential for priming cytotoxic CD8+ T cell responses 1. In cancer contexts, higher densities of CLEC9A+ DCs correlate with improved survival outcomes in nasopharyngeal carcinoma and better responses to immunotherapy 45. The receptor's therapeutic potential is demonstrated by antibody-mediated targeting strategies that deliver tumor antigens specifically to CD141+ DCs, enhancing vaccine immunogenicity and CD8+ T cell activation 6. Additionally, CLEC9A+ DC recruitment positively correlates with cytotoxic CD8+ T cell responses in inflammatory diseases like COPD 7.