The present invention provides methods of characterising a DNA sample obtained from a tumour to produce an interpreted profile of the tumour based on a combination of a range of tests on the tumour, the tests including a selection from: determining a catalogue of base substitution signatures which are present in the sample; determining a catalogue of rearrangement signatures which are present in the sample; determining a catalogue of insertion/deletion signatures which are present in the sample; determining the overall copy number profile in the sample and identifying putative driver mutations present in the sample.