CD4 naïve T cells are a primary subset of T lymphocytes which can differentiate into different functional subtypes (such as T helper types 1 and 2) and then exert important immunity functions.[25] The lack of CD4 naïve T cells is highly correlated with immunodeficiency diseases.[26] While the roles of CD4 naïve T cells in the development of septic shock have not been previously reported, we discovered that CD4 naïve T cells were significantly downregulated in septic shock. The gene discussed is CD4; the disease is immunodeficiency disease.