Figure 3.

Clonal Evolution and Drug Resistance. Acquired drug resistance may emerge as a consequence of the selective expansion of: a) the de novo development of resistance in a previously sensitive clone (e.g. as a consequence of treatment induced mutagenesis, or tumour‐intrinsic genomic instability) b) a pre‐existing resistant minor subclone or c) multiple pre‐existing or de novo resistant subclones, which may be present across one or multiple sites of disease.