S100B and atrial fibrillation: Moreover, higher concentrations of alarmins such as HMGB1, S100β, heat shock protein 70, cell-free DNA and S100 proteins have been found within AF, maternal blood or even gestational tissues (placenta, FM) in cases of pPROM or chorioamnionitis [62,63,64,65,66,67,68,69]; these increased amounts of DAMPs, which can lead to an inflammatory stimulation by interacting with PRRs, might be the consequence of oxidative stress or senescence [70,71].