See alternative names

Intestinal 15 kDa protein,
Intestinal bile acid-binding protein,
Fatty acid-binding protein 6,
Ileal lipid-binding protein

Uniprot Function Description

Binds to bile acids and is involved in enterohepatic bile acid metabolism. Required for efficient apical to basolateral transport of conjugated bile acids in ileal enterocytes (By similarity). In vitro binds to bile acids in the order: deoxycholic acid > cholic acid > chenodeoxycholic acid and respective BA conjugation modifies affinities in the order taurine-conjugated > glycine-conjugated > unconjugated bile acids. Stimulates gastric acid and pepsinogen secretion (By similarity).

Essential for the survival of colon cancer cells to bile acid-induced apoptosis.


Precision (repeatability) is calculated from linearized NPX values over LOD.

Within run precision Coefficient of Variation (CV)
Between run precision Coefficient of Variation (CV)

Dilution factor

For optimal assay readout, Olink Explore is run using different dilutions of the original samples (undiluted, 1:10, 1:100 or 1:1000). The dilution factor for this assay is noted below and should be taken into account when estimating the appropriate addressable biological concentration of the protein based on the in vitro validation data.

Dilution factor

Sample distribution plot

The plot below shows the levels of protein measured in a number of commercial plasma samples. Healthy subjects are shown in blue and samples obtained from patients with a range of diseases are shown in red. The latter include inflammatory, cardiovascular, autoimmune & neurological diseases, as well as cancer. The data is shown to give a general idea of the sort of NPX range to expect, but cannot cover all potential levels that may be seen in clinical samples. The y-axis shows NPX above background, which is defined as the median of negative control measurements and used to define the expected background level (zero).