APOA1 and breast cancer: In the METABRIC cohort, APOA1/C3/A4/A5 copy number loss was significantly associated with shorter breast cancer-specific survival in both the univariate analysis (hazard ratio [HR] = 1.33, P = 0.011) (Supplementary Fig. 5C) and the multivariate analysis (HR = 1.44, P = .007) (Table 3).