To directly demonstrate the role of xbp-1 in protecting intestinal cells against Cry5B, the intestinal specific app-1 promoter [17] was used to drive expression of xbp-1 in xbp-1(zc12) mutant animals to determine if expression in the intestine is sufficient to rescue the Hpo phenotype. As a negative control, GFP was similarly expressed under control of the app-1 promoter in xbp-1(zc12) mutant animals. In control animals, expression of the GFP solely in intestinal cells was confirmed (data not shown). As expected, the majority of wild-type N2 animals showed only a low-modest degree of intoxication upon exposure to 25% Cry5B-expressing E. coli ( Figure 3A , B; they were smaller and somewhat paler than the wild-type worms on control plates but were still quite active). Also as predicted, both xbp-1(zc12) mutant animals and xbp-1(zc12) mutant animals transformed with app-1::GFP were Hpo and intoxicated to similar extents ( Figure 3A , B; most animals were very pale, small, and inactive). In contrast, xbp-1(zc12) worms expressing xbp-1 under the app-1 promoter were significantly healthier than either untransformed or app-1::GFP transformed xbp-1(zc12) animals fed with Cry5B ( Figure 3A, B) . However, these app-1::xbp-1-transformed xbp-1(z12) worms were not as healthy as wild-type N2 under the same conditions. This partial rescue could indicate the expression of the artificial xbp-1 transgenes did not fully recapitulate wild-type xbp-1 expression levels and/or that there is some role for the ire-1 -xbp-1 pathway in other cell types.