ASS1 and citrullinemia type I: Importantly, as non-viral agents, EVs derived from wild-type human LSCs were also capable of restoring enzymatic deficiency in human LSCs isolated from the liver of a patient with type I citrullinemia, suggesting that these nanometer-sized vesicles can transfer argininosuccinate synthase (ASS1 enzyme) and its mRNA, hence achieving gene therapy for certain inherited disorders [119].