TOP2A and neoplasm: The C4 cell population showed high expression of Hmgb2, Ube2c, Cenpf, Top2a, and Mki67, among which Hmgb2 and Ube2c are associated with tumor cell proliferation and drug resistance 18, 19, Cenpf and Top2a are key regulators of mitosis 20, 21, and Mki67 serves as a core marker of cell proliferation 22, Together, these data indicate that C4 cells exhibit robust proliferative activity (Figure 5C).