FLI1 and sarcoma: We found that PRMT1 and PRMT5 expression, along with MEP50 the obligate cofactor of PRMT5, are generally higher in multiple sarcoma types, including EWSR1::FLI1 and EWSR1::ERG fusion-positive ES tumours, than in breast and lung cancer (Figure 1A, Supplementary Figure 1A).