This gene encodes a member of the WAP-type four disulfide core domain family. The WAP-type four-disulfide core domain contains eight cysteines forming four disulfide bonds at the core of the protein, and functions as a protease inhibitor in many family members. This gene is mapped to chromosome 16q24, an area of frequent loss of heterozygosity in cancers, including prostate, breast and hepatocellular cancers and Wilms' tumor. This gene is downregulated in many cancer types and may be involved in the inhibition of cell proliferation. The encoded protein may also play a role in the susceptibility of certain CD4 memory T cells to human immunodeficiency virus infection. Alternative splicing results in multiple transcript variants.