Fifty-four percent of plasma samples had a concordant gain or loss in the primary tumour.65 The presence of CNA in plasma has also been associated with clinical outcome, and their analyses have revealed new resistance mechanisms in patients with prostate cancer or NSCLC such as androgen receptor (AR) amplification and TMPRSS2‐ERG fusion or MYC amplification, respectively.67,68. The gene discussed is ERG; the disease is prostate cancer.