IL6 and infection: After trauma, surgery and infection, the body can stimulate immune cells and affected cells to produce a variety of cytokines that cause an inflammatory response and produce immunomodulatory effects.[30] IL-6 is an important inflammatory factor in the neuroendocrine-immune system, and elevated levels of IL-6 can help improve the body specific immune function during inflammatory responses.[31] Therefore, this study used these indicators to reflect the cellular immune function of the patients.