In addition to their ability to regulate HIV infection, whey acidic proteins are recognised for their anti-inflammatory activity, e.g. they are able to suppress lipopolysaccharide (LPS)-stimulated production of cytokines like tumour necrosis factor (TNF)α [30]; and ps20 can suppress toll-like receptor (TLR)3-mediated induction of IFNα in human cells, which may contribute to its infection-enhancing activity (Vyakarnam et al., unpublished). Here, WFDC1 is linked to HIV infectious disease.