SLPI and HIV infectious disease: It was recently demonstrated that serpins are potential inhibitors of HIV-1 replication in the blood and mucosa [16]: (1) Early during HIV infection, serpin levels in the blood increase rapidly to levels in the range of their in vitro inhibitory activity [32]; (2) The serpin, secretory leukocyte inhibitor (SLPI), has been described as an important HIV-1 inhibitory factor in saliva [33]; (3) serpins are highly expressed in the cervical fluids of exposed but uninfected sex workers [19], and (4) serpins are highly expressed in HIV long-term non-progressors [20], [24].