S100A9 and chorioamnionitis: In this work, we used our model to determine whether GBS-induced chorioamnionitis induces a sexually dichotomous innate inflammatory process driven by IL-1β, IL-1-induced chemokine cytokine-induced neutrophil chemoattractant-1 (CINC-1/CXCL1) attracting PMNs, and PMN-produced S100A9 and MMP-8.