According to the iNOS/ARG1 ratio, CLP initially polarized PE cells to the M1 phenotype (at 6 h after CLP), and subsequently to the M2 phenotype (at 20 h after CLP), which is consistent with a conceptual immunological framework indicating that immunosuppression is more severe in the late than in the early phase after sepsis [3]. This evidence concerns the gene NOS2 and Sepsis.