The aim of this study was to investigate the mechanism of Herceptin resistance through the IGF1R pathway in HER2 positive breast cancer....In clinical research, we found that decreased miR-98-5p level or increased IGF2 level significantly associated with poor treatment response and poor overall survival (OS), poor recurrence free survival (RFS) and poor distant metastasis-free survival (DMFS) in HER2-positive breast cancer....MiR-98-5p and IGF2 might potential candidates for predicting Herceptin sensitivity...