ERBB2 and breast carcinoma: The number of at‐risk patients with HER2 enriched‐subtype breast cancer was lower than that of patients with luminal A‐subtype breast cancer, but the upper quartile of RFS was significantly different: 12.96 months for the low‐FAM189A2 cohort and 28 months for the high‐FAM189A2 cohort (HR = 0.45, log‐rank P = 4.1e‐05, FDR = 1%) (Fig 1F).