“…With the discovery of testis-specific protein 1 (Tpx-1, CRISP-2; Hardy et al, 1988;Kasahara et al, 1989) and specific granule protein of 28 kDa (SGP28, CRISP-3; Haendler et al, 1993;Kjeldsen et al, 1996), four CRISPs (CRISP-1-CRISP-4) have now been identified in mammalian tissues. Furthermore, it has also been shown that CRISPs are widely distributed in non-mammalian species, including Xenopus (Olson et al, 2001), Caenorhabditis elegans (Ookuma et al, 2003) and the venoms of lizards (Nobile et al, 1994(Nobile et al, , 1996Morrissette et al, 1995), cone snails (Milne et al, 2003;Hansson et al, 2006) and snakes (Yamazaki & Morita, 2004, 2007. Although clear evidence for either function or target molecules is lacking for most of the CRISPs, including endogenous CRISPs, recent evidence has emerged suggesting that some exogenous CRISPs derived from venomous snakes may function as ion-channel blockers (Nobile et al, 1994(Nobile et al, , 1996Brown et al, 1999Brown et al, , 2003Yamazaki, Brown et al, 2002;Yamazaki, Koike et al, 2002;Wang et al, 2005).…”