Further investigation of the relationship between HER2 targeted therapy efficacy and IGF-1 level, interacted with obesity (Figure S2) showed that only in patients with BMI <24.0 kg/m2 and receiving adjuvant targeted therapy, those with higher expression of IGF-1 had a significant superior OS than those with lower IGF-1 (Log-rank P < 0.001; Figure S2B). Here, ERBB2 is linked to obesity disorder.