Furthermore, certain cell cycle–related proteins, including TOP2A, PCNA, MCM2, MCM4, MCM5, MCM6, and MCM7, have also been reported (69–71) to facilitate cancer cell proliferation, and the enhanced expression of these cell cycle–related proteins may contribute to uncontrolled ESCC cell proliferation. Here, TOP2A is linked to esophageal squamous cell carcinoma.