ERBB2 and breast cancer: In the multivariate analysis of HER2-negative luminal subtype considering variables such as age, T stage, N stage and adjuvant treatment, high CPCC was significantly associated with poor DFS (HR, 4.789; 95%CI, 1.662–13.799; P = 0.004), whereas the Ki-67LI was not (Table 3), suggesting that CPCC is a significant survival indicator, and CKAP2 is a better prognostic marker than Ki-67 in HER2-negative luminal subtype of breast cancer.