細胞周期
Cell cycle checkpoint control protein RAD9A is a protein that in humans is encoded by the "RAD9A" gene."Rad9" has been shown to induce G2 arrest in the cell cycle in response to DNA damage in yeast cells. "Rad9" was originally found in budding yeast cells but a human homolog has also been found and studies have suggested that the molecular mechanisms of the S and G2 checkpoints are conserved in eukaryotes. Thus, what is found in yeast cells are likely to be similar in human cells.