GLUL and Hyperammonemia: As hepatic UCEs and GS play pivotal roles in ammonia detoxification (Figure 2A), it is not surprising that hepatic deletion of GS triggers systemic hyperammonemia, symptoms commonly associated with cerebral damage, increased locomotion, impaired fear memory, and slightly reduced life span (Qvartskhava et al., 2015; Hakvoort et al., 2017).