CLEC2B (C-type lectin domain family 2 member B) is a membrane-bound protein expressed on myeloid cells that functions as a ligand for the NK cell activating receptor NKp80/KLRF1, stimulating NK cell cytotoxicity and cytokine production. The CLEC2B-KLRB1 ligand-receptor pair represents a key immunoregulatory interaction between epithelial cells and NK/T cells 1, as well as between macrophages and NK cells in acute myeloid leukemia 2. Beyond its canonical NK cell activation role, CLEC2B exhibits broader disease relevance. It is differentially expressed across multiple cancer types with associations to immune cell infiltration and checkpoint regulation 3. CLEC2B has been identified as a prognostic biomarker in melanoma metastasis, where high-risk signatures containing CLEC2B correlate with reduced CD8+ T cell infiltration and poor prognosis 4, and as part of a validated 6-gene prognostic signature for melanoma patient survival 5. Additionally, CLEC2B demonstrates robust expression in immune cells (B cells, NK cells, monocytes) in preeclampsia, enriching pathways of immune activation and cytokine signaling 6. Age-dependent matrisome transcriptome analysis identified CLEC2B among genes with tissue-specific expression changes during aging 7, and elevated CLEC2B expression distinguishes drug-resistant tuberculosis 8. These findings establish CLEC2B as both a functional immune regulator and a clinically relevant biomarker across multiple pathological contexts.