Overview of proposed pathways of infectious and non-infectious labor. AP-1, activator protein 1; CCL5, chemokine (C-C motif) ligand 5; dsRNA, double-stranded RNA; IL, interleukin; LMW-HA, low molecular weight hyaluronan; LPS, lipopolysaccharide; LTA, lipoteichoic acid; NFκB, nuclear factor κB; PAF, platelet-activating factor; PGN, peptidoglycan; STAT, signal transducers and activators of transcription; TNF, tumor necrosis factor.