LY75-CD302 (CD205/DEC-205) functions as an endocytic receptor that captures antigens from the extracellular space and directs them to specialized antigen-processing compartments for presentation by dendritic cells 1. This C-type lectin family member exhibits distinct functional modes: on immature dendritic cells, it actively internalizes ligands through endocytosis, while upon maturation, CD205 undergoes surface redistribution and loses endocytic capacity, transitioning to a non-endocytic role 1. Additionally, LY75-CD302 causes reduced proliferation of B-lymphocytes. The gene can undergo alternative splicing to generate fusion proteins with DCL-1, a mechanism particularly prevalent in Hodgkin lymphoma cell lines where the DEC-205/DCL-1 fusion mRNA predominates 2. Clinically, germline pathogenic variants in LY75-CD302 have been identified as overrepresented in early-onset ovarian cancer patients (≤30 years old), pointing toward impaired immune response as a potential cancer predisposition mechanism 3. These findings suggest LY75-CD302 plays a critical role in antigen presentation and immune regulation, with dysregulation potentially contributing to both hematologic malignancies and solid tumors.