KL and periodontitis: Transcriptional regulation is a primary function of histone Kla, with Kla-mediated transcriptional programs modulating diverse physiological and pathological processes, such as macrophage phenotype regulation [18], tumor growth [19] and metastasis [20], progression of periodontitis [21], osteogenesis [22], osteoblast differentiation [23], development of preimplantation embryos [24], and meiosis in mouse oocytes [25] (Figure 3).