ERBB2 and neoplasm: As shown in Figures 1A, B, the AUC of HER2 status, Ki67 index, tumor size, and Emean in the training cohort were 0.681, 0.636, 0.778, and 0.770, respectively, and the AUC in the validation cohort were 0.688, 0.604, 0.753, and 0.740, respectively, which further verified the performance of these four independent factors for NSLN metastasis.