CEACAM19 is a cell adhesion molecule belonging to the carcinoembryonic antigen-related family, localized to the plasma membrane where it mediates heterophilic and homophilic cell-cell adhesion through protein-binding interactions. Functionally, CEACAM19 serves as a receptor for bacterial adhesins; specifically, it interacts with Helicobacter pylori's HopQ protein to support type IV secretion system-dependent activation of non-canonical NF-κB signaling 1. CEACAM19 exhibits oncogenic properties across multiple cancer types. In gastric cancer, CEACAM19 knockdown suppresses tumor progression by inactivating PI3K/Akt and NF-κB signaling pathways, reducing MMP2/MMP9 expression and inhibiting cell proliferation, migration, and invasion 2. Similarly, CEACAM19 is significantly overexpressed in breast cancer (77.6% of tumors show high expression), with elevated levels particularly in ER/PR-negative subtypes, suggesting potential as a therapeutic target 3. The gene undergoes complex alternative splicing generating at least 15 novel transcripts with broad expression across cell lines, positioning these variants as putative diagnostic/prognostic biomarkers 4. Clinically, CEACAM19 methylation status contributes to a multi-omics prognostic signature predicting head and neck cancer survival 5, and its cis-genetic variation associates with Alzheimer's disease risk through transcriptome-wide analysis 6. The CEACAM family broadly participates in tumor immunotherapy development as emerging therapeutic targets 7.