[5] It was formerly known as "Long palate, lung and nasal epithelium carcinoma-associated protein 4" encoded by the LPLUNC4 gene.

The BPIFB4 gene sequence predicts 4 transcripts (splice variants); 3 isoforms have been well characterized.

[13] The BPI fold creates apolar binding pockets that can interact with hydrophobic and amphipathic molecules, such as the acyl carbon chains of lipopolysaccharide found on Gram-negative bacteria, but members of this family may have many other functions.

[17] In the olfactory mucosa it is believed to act similarly to other BPIFB proteins in the innate immune response to bacterial exposure.

Furthermore, increased nitric oxide from activated eNOS promotes the sprouting of new capillaries (angiogenesis) in conditions when ischemia occurs[21] caused by the blockage of arteries by atherosclerosis, for example.

LAV-BPIFB4 is believed to be immunomodulatory due to a variety of mechanisms involving macrophages and monocytes that can counteract low-grade chronic inflammatory conditions.

BPIFB4 also reduces T-cell activation demonstrated by suppression of T cell proliferation and elevation of circulating levels of interleukins IL-23, IL-27 and atheroprotective IL-33.