[9] 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.

BPIFB3 was first directly identified in a screen of rat olfactory epithelium as RYA3[12] and was recognized to be a member of the BPI fold superfamily.

[13][11] In humans, it was formerly known as "Long palate, lung and nasal epithelium carcinoma-associated protein 3" encoded by the LPLUNC3 gene.

[15][16] Its cytoplasmic location appears to be localized to the endoplasmic reticulum (ER) and influences the replication of coxsackievirus B; when BPIFB3 is knocked out in experimental systems coxsackievirus B replication dramatically increases.

It has been within observed in the ER to be physically associated with another family member, BPIFB6, and modulation of either of these two proteins can enhance or suppress enteroviral release from cells.