Proteomics-based approaches, such as LC-MS/MS and MALDI-ToF/ToF MS, may be used to assess the efficacy of method optimization for protein extraction from urine samples [228], for detecting the upregulated, stage-specific, or biomarker proteins involved in the early screening detection and monitoring of invasive BC progression [90], and to identify the significant urinary changes in protein profiles before a breast tumor becomes palpable [89] or the specific urinary proteome alteration in HER2-enriched BC [229]. Here, ERBB2 is linked to breast cancer.