Mutants defective in the cell signaling or other defense molecules of C. elegans were either more susceptible (defective in nsy-1, sek-1, pmk-1, ced-3, ced-9, skn-1, or daf-16) or more resistant (defective in age-1 or dbl-1) to DT104 infection than the WT except for the mutant defective in sod-3. This evidence concerns the gene SOD3 and infection.