At the depths of sequencing we achieved with TAm-Seq analysis, we were unable to detect these mutants in the whole blood specimens; however, the deep mutation-specific sequencing we performed using the Nextera capture did permit the detection of blood-specific metastatic clones that were unique to the primary tumour 3 years after removal of the prostate, strongly suggesting that the acquisition of a separate TP53 mutation in these blood-specific clones led to their ability to metastasize (Fig. 1). The gene discussed is TP53; the disease is neoplasm.