The challenging parts of this therapy are as follows: at the beginning, the patient suffered from a malnutrition-infection cycle with thrombosis, which made it difficult to obtain a central venous line; his intestinal failure with poor nutritional status made enteral nutrition impossible at first, which suggested parenteral nutrition might be the first choice for his condition; hepatic dysfunction with a maximum ALT of 1433 U/L also limited nutrition therapy. The gene discussed is GPT; the disease is malnutrition.