ERBB2 and breast cancer: American Society of Clinical Oncology (ASCO) outlines genomic testing's utility, emphasizing prognostic and diagnostic potential.<h4>Objectives</h4>This review succinctly explores NGS's evolution and clinical applications of NGS in breast cancer, thereby guiding future research to enhance patient care.<h4>Methods</h4>Comprehensive literature searches were conducted using databases such as PubMed, Google Scholar, and ResearchGate, focusing on keywords including breast cancer, <i>HER-2 low breast cancer, circulating tumour DNA, single-cell RNA sequencing, and next-generation sequencing</i>.