S100A8 and periodontitis: Periodontitis induced the development of GMPs toward the neutrophil lineage at the expense of monocytic differentiation, as indicated by the dynamic changes in monocytic signature genes (F13a1, Irf8, and Ly86) and neutrophil-associated genes (Camk1d, S100a8, and S100a9) along the trajectory (Figure 2I).