Davis AA, Zhang Q, Gerratana L, et al. - Since liquid biopsies [circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs)] can be used to understand disease prognosis, tumor heterogeneity, and dynamic response to treatment in metastatic breast cancer (MBC), researchers sought to analyze a novel, 180-gene ctDNA panel and the relationship of this platform with CTCs and CTC clusters. In total, 40 samples from 22 individuals with MBC were involved. The authors report on a novel ctDNA platform that identified genomic alterations in the vast majority of patients studied, further suggesting potential clinical utility to capture the heterogeneity of the disease and track disease. Particular genomic profiles were associated with detection of CTCs and CTC clusters.