PLK1 and neoplasm: Based on our previous research (Cheng et al., 2021), 20 prognostic biomarkers (ESR1, PGR, ERBB2, MKI67, PLAU, ELAVL1, EGFR, BTRC, FBXO6, SHMT2, KRAS, SRPK2, YWHAQ, PDHA1, EWSR1, ZDHHC17, ENO1, DBN1, PLK1 and GSK3B) (Supplementary Section A) and 10 clinical features (age, menopausal state, tumor size, radiotherapy, chemotherapy, hormone therapy, neoplasm histologic grade, cellularity, surgery-breast conserving and surgery-mastectomy) were included in the experiments.