Copy number heterogeneity between different regions of a metastatic melanoma tissue sample. A) Representative H&E staining of section of FFPE block from Tumor 1 before coring and after coring. Inserts in the ‘after’ panel are H&E stains from the bottom of the core fragment used for DNA isolation. Scale bar next to whole section represents 1 mm, bars next to cores represent 100 μm. B) Hierarchical clustering and heatmap of copy number data from Tumor 1 cores. Black regions represent normal copy number (2), green represents amplifications, red deletions.