Phospho-Histone H3 (Ser10) is a critical epigenetic marker associated with chromosome condensation and mitotic progression. This phosphorylation event typically occurs during the G2 to M phase transition and is essential for chromatin condensation, making it a specific indicator of mitotic cells. It is regulated by kinases such as Aurora B and plays a significant role in mitotic chromosome condensation and decondensation. Additionally, H3 Ser10 phosphorylation has been implicated in transcriptional regulation and early gene expression, and its dysregulation has been linked to neoplastic cell transformation and cancer.