ARID1A and metastatic neoplasm: Second, by comparing the mutation CCF between the paired pretreatment primary and posttreatment progressed metastasis samples, we found that SNVs in genes such as TP53, ARID1A and TRAF3 and CNVs such as ATG13 deletion, KMT2D amplification and ARID1A deletion were evidently selected in posttreatment progressed metastatic tumours (Fig. 2e).