Seroatlas · Human Serome Atlas

BPIFB4

BPI fold-containing family B member 4

Also known as: BPIB4_HUMAN, C20orf186, dJ726C3.5, LPLUNC4

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession: P59827
Gene: BPIFB4
Ensembl: ENSG00000186191
Chromosome: 20
Canonical length: 614 aa
Protein class: Predicted secreted proteins
Subcellular location: Actin filaments,Cytosol
Secretome location: Secreted - unknown location

OverviewNCBI Gene

Predicted to enable lipid binding activity. Located in actin cytoskeleton and cytosol. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

614 residues, UniProt reviewed canonical sequence.

>P59827|BPIFB4
     1  MWMAWCVAAL SVVAVCGTSH ETNTVLRVTK DVLSNAISGM LQQSDALHSA LREVPLGVGD
    61  IPYNDFHVRG PPPVYTNGKK LDGIYQYGHI ETNDNTAQLG GKYRYGEILE SEGSIRDLRN
   121  SGYRSAENAY GGHRGLGRYR AAPVGRLHRR ELQPGEIPPG VATGAVGPGG LLGTGGMLAA
   181  DGILAGQGGL LGGGGLLGDG GLLGGGGVLG VLGEGGILST VQGITGLRIV ELTLPRVSVR
   241  LLPGVGVYLS LYTRVAINGK SLIGFLDIAV EVNITAKVRL TMDRTGYPRL VIERCDTLLG
   301  GIKVKLLRGL LPNLVDNLVN RVLADVLPDL LCPIVDVVLG LVNDQLGLVD SLIPLGILGS
   361  VQYTFSSLPL VTGEFLELDL NTLVGEAGGG LIDYPLGWPA VSPKPMPELP PMGDNTKSQL
   421  AMSANFLGSV LTLLQKQHAL DLDITNGMFE ELPPLTTATL GALIPKVFQQ YPESCPLIIR
   481  IQVLNPPSVM LQKDKALVKV LATAEVMVSQ PKDLETTICL IDVDTEFLAS FSTEGDKLMI
   541  DAKLEKTSLN LRTSNVGNFD IGLMEVLVEK IFDLAFMPAM NAVLGSGVPL PKILNIDFSN
   601  ADIDVLEDLL VLSA

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against BPIFB4 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability: Secreted
Secreted: Yes
Transmembrane segments: 0
Mean surface accessibility (rSASA): 0.36
Highest tissue expression: 7.5 nTPM

Expression across tissuesHPA

Tissue

pituitary gland: 7.5 nTPM
heart muscle: 0.5 nTPM
testis: 0.5 nTPM
adipose tissue: 0.4 nTPM
salivary gland: 0.4 nTPM
choroid plexus: 0.2 nTPM

Single-cell type

oocytes: 9.2 nCPM
pituitary stem cells: 5.2 nCPM
mucous neck cells: 5.1 nCPM
platelets: 4.2 nCPM
undifferentiated spermatogonia: 2.4 nCPM
epicardial cells: 2.3 nCPM

Immune cell

basophil: 0 nTPM
classical monocyte: 0 nTPM
eosinophil: 0 nTPM
gdT-cell: 0 nTPM
intermediate monocyte: 0 nTPM
MAIT T-cell: 0 nTPM

Brain region

choroid plexus: 1.4 nTPM
midbrain: 0.3 nTPM
amygdala: 0 nTPM
basal ganglia: 0 nTPM
cerebellum: 0 nTPM
cerebral cortex: 0 nTPM

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance): 1.29
gnomAD pLI: 0
gnomAD missense Z: -0.72
DepMap mean gene effect: -0.1
DepMap dependency class: selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Molecular functions

lipid binding

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads BPIFB4 as an antibody target. Whether an autoantibody or antibody against BPIFB4 could matter depends on whether native BPIFB4 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

BPIFB4 is annotated as secreted, so native BPIFB4 circulates and is directly accessible to antibodies. Secreted and cell-surface proteins are the autoantibody targets most likely to act like drugs, blocking or depleting the native protein.

Annotation status

The present source text does not explicitly label BPIFB4 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

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