ERBB2 and breast cancer: We used TCGA databases and found that the expression level of IGF2 in breast cancer tissues was lower than that in normal tissues and had no correlation with the overall survival of breast cancer, the expression of IGF2 in HER2-positive breast cancer tissues was lower than that in HER2-negative breast cancer tissues, all the above suggesting that IGF2 may not be directly related to the occurrence and development of breast cancer.