ATF1 and sarcoma: Five sarcoma FFPE samples were included in the analysis where translocations had previously been detected by RT-qPCR involving EWSR1. Rearrangements in EWSR1 were detected in four out of the five FFPE samples (80%) leading to fusion genes of EWSR1 with partners ATF1 (detected in two samples), FLI1 and CREB1 (Supplementary Figure 6).