CDK12 and neoplasm: For example, in a tumour with 28 SV breakpoints in two clusters around the highly amplified CDK12-ERBB2 (copy number = 115) and STAT5B-STAT3 (copy number = 72) loci, reconstruction suggested there were multiple ecDNA circles or segments carrying either ERBB2 or STAT5B alone, plus some carrying both amplicons (copy number = 25).