MAPK1 and breast cancer: According to the criteria of DC, BC, CC and EC (≥ 7.27, ≥ 82.48, ≥ 0.41, and ≥ 0.10 respectively), 12 key targets were identified (Table 2), including 5 targets: MAPK3, EGFR, VEGFA, MAPK1 and AKT1 with a high degree value.