CEH-18 plays a role in host defence.

<p><b>A.</b> Ratio of green fluorescence (GFP) to size (TOF) in wild-type (IG274) or <i>ceh-18</i>(<i>mg57</i>) mutant (IG1714) worms carrying <i>frIs7</i>, infected or not with <i>D</i>. <i>coniospora</i> for 16 h (yellow and blue, respectively; data for IG274 is as Fig 3B in [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007494#pgen.1007494.ref053" target="_blank">53</a>]), and IG274 worms treated with RNAi against <i>sta-1</i> (control) or <i>ceh-18</i> and, from left to right, exposed to high salt (purple; <i>cpsf-2(RNAi)</i> is a positive control, <i>sta-2(RNAi)</i> a negative control [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007494#pgen.1007494.ref011" target="_blank">11</a>]), in worms also expressing GPA-12* in the epidermis, and in the <i>rde-1</i>(<i>ne219</i>);<i>wrt-2p</i>::<i>RDE-1</i> background and infected by <i>D</i>. <i>coniospora</i>. For the latter 2 panels, <i>sta-2(RNAi)</i> is a positive control. A minimum of 45 worms was used for each condition. The black bar represents the mean value; *** p<0.001, **** p<0.0001, relative to <i>sta-1</i>(RNAi), Dunn’s test; for the other conditions there is not a significance decrease. The results of the 3 right panels are unpublished results from [<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007494#pgen.1007494.ref011" target="_blank">11</a>], representative of at least 4 independent experiments. <b>B.</b> Quantitative RT-PCR analysis of the expression of several genes in the <i>nlp-29</i> cluster in wild-type worms, <i>sta-2</i> and <i>ceh-18</i> mutants infected by <i>D</i>. <i>coniospora</i>; results are presented relative to those of uninfected worms. Data (with average and SD) are from three independent experiments. **, p < 0.001; *, p < 0.01; 1-tailed ratio paired t test. <b>C.</b> Results of 2 independent tests of survival of <i>rde-1</i>(<i>ne219</i>);<i>wrt-2p</i>::<i>RDE-1</i> worms treated with RNAi against <i>sta-1</i>, <i>sta-2</i>, <i>akir-1</i> or <i>ceh-18</i>, infected with <i>D</i>. <i>coniospora</i> and cultured at 25°C (n>65 for all tests). The difference between the <i>sta-1(RNAi)</i> and <i>ceh-18(RNAi)</i> animals is highly significant in both trials (p<0.0001; one-sided log rank test).