The median serum exosomal lncRNA DANCR expression was used as a cut‐off value, and all 120 BC patients were classified into two groups: high serum exosomal DANCR expression group (n = 60) and low serum exosomal DANCR expression group (n = 60). As illustrated in Table 1, high serum exosomal lncRNA DANCR expression occurred more frequently in BC cases with positive lymph node metastasis (p = 0.0080), negative ER status (p = 0.0150), negative HER2 status (p = 0.0009), and advanced TNM stage (p < 0.0001). The gene discussed is ERBB2; the disease is breast cancer.