ESR1 and cancer: Since WGS is far more accurate in identifying CNVs boundaries, it can provide further insights into well-known cancer associated genes, such as focal amplification of FOXA1 in MCF7 versus broad copy number gain in GATA3 and partial gain of ESR1. By comprehensively identifying the genomic features of these models, the field can now choose appropriate models to examine the functional significance of genes or pathways of interest.