CHEK1 and breast cancer: In this study, we revealed the negative relationship of between PPP2R2A and pChk1-S317 is associated with the survival of breast cancer patients (Fig. 8G and H), potentially indicating the status of PPP2R2A or PPP2R2A-Chk1 pathway may also serve as a potential biomarker to predict the prognosis of tumor patients and guide tumor treatment.