Abstract:Breast cancer is a highly heterogeneous tumor, and chromosome amplification is one of the main factors driving the heterogeneity of tumor cells. Amplification of the 1q21 region is the most common event of genome copy number change in human breast cancer, and patients with breast cancer with this region amplification are at increased risk of disease progression, drug resistance, and death. Chromosomal aberrations associated with the expansion of 1q21 can lead to the dysregulation of oncogene expression in this region, thereby inducing breast cancer metastasis, chemical resistance, and tumor recurrence. In this review, the oncogenes related to 1q21 amplified breast cancer and their functions were summarized, in order to provide scientific basis for the development and optimization of the diagnosis and treatment of 1q21 amplified breast cancer.