I would suggest you look at MYC gene whose amplification correlates with breast tumor progression.
MYC is a proto-oncogene which functions as a transcription factor regulating up to 15% of all human genes. MYC is regulated at multiple levels, and the protein is a downstream effector of several signaling pathways. In breast cancer cells, MYC target genes are involved in cell growth, transformation, angiogenesis and cell-cycle control.
MYC amplification is emerging as an important predictor of response to HER2-targeted therapies and its role in BRCA1-associated breast cancer makes it an important target in basal-like/triple-negative breast cancers.
You may want to refer to the articles I have attached below for your reference. They will be helpful.
Article Plasma C-MYC level manifesting as an indicator in progressio...