In contrast, copy number deletions in NOTCH2 (3/6), NRAS (3/6), RAF1 (3/6), MPL (2/6) and PIK3CB (2/6) were found recurrent and specific to primary tumours, whereby deletions in IRF4 (2/6), MUC4 (2/6), RARA (2/6), STAT3 (2/6), STAT5B (2/6) and TAF15 (2/6) were found recurrent and only specific to metastatic tumours. Here, IRF4 is linked to metastatic neoplasm.