Plays a role in the stress response to heavy metals such as copper, probably in a kgb-1-dependent manner. By heavy metal stress conditions, in response to Cu(2+). RNAi-mediated knockdown results in partial sensitivity to Cu(2+) ions with less than 70% of animals reaching adulthood 4 days after egg laying. Belongs to the glycosyl hydrolase 25 family. Weak similarity to other lysozymes and lacks the conserved active site.