At the intervention level, high-dose arginine butyrate (ArgB) combined with Interleukin-2 (IL-2) has severe hepatotoxicity in metastatic CRC (60% incidence of grade 4 cholestasis in the ≥4 g·kg−1·d−1 group), and the human tolerable dose (3 g·kg−1·d−1) is much lower than the effective dose in animal experiments (10 g·kg−1·d−1), making it difficult to form a standardized protocol [30,31,32,33]. The gene discussed is IL2; the disease is cholestasis.