TP53 and PIK3CA emerge as the most frequently reported driver alterations in primary breast cancer; however, in MBC, additional alterations in different metastatic sites add complexity to the overall genetic profile.4 Monitoring techniques currently used in practice, though, lack the capability to identify the onset of disease progression and treatment resistance at an early stage, thus hindering the timely transition to a more potent and effective treatment strategy. Here, PIK3CA is linked to breast cancer.