BPFIB2 (BPI Fold Containing Family B Member 2), also known as LPLUNC1 or C20orf186. is a protein encoded by the *BPIFB2* gene located on chromosome 20q11.21. It belongs to the bactericidal/permeability-increasing protein (BPI) family, which plays roles in innate immunity, particularly in defense against Gram-negative bacteria. BPIFB2 contains a conserved BPI domain implicated in lipid-binding or pathogen-associated molecular pattern recognition. While its exact biological function remains under investigation, BPIFB2 is predominantly expressed in mucosal tissues, including the respiratory tract, oral cavity, and salivary glands, suggesting involvement in maintaining mucosal immunity and homeostasis.
Antibodies targeting BPIFB2 are valuable tools for studying its expression, localization, and functional roles. Research indicates that BPIFB2 may participate in inflammatory responses, cell differentiation, and tumorigenesis. Dysregulation of BPIFB2 has been observed in cancers (e.g., nasopharyngeal carcinoma, lung adenocarcinoma) and chronic inflammatory conditions, highlighting its potential as a biomarker or therapeutic target. Commercial BPIFB2 antibodies are typically developed in rabbit or mouse hosts, validated for applications like immunohistochemistry, Western blotting, and ELISA. However, specificity challenges may arise due to homology with other BPI family members. Ongoing studies aim to clarify its molecular mechanisms and clinical relevance in disease contexts.