The protein CaM Kinase II plays a significant role in controlling when and where neuropeptides are released from neurons, researchers have found using mutant C. elegans. Using a method called "forward genetics," the researchers randomly screened thousands of mutant worms for defects in neuropeptide storage and unexpectedly identified mutant worms lacking CaM Kinase II. Further analysis revealed that CaM Kinase II plays a significant role in controlling when and where neuropeptides are released from neurons.