FLI1 and neoplasm: We also demonstrated that ETS1 could function as a transcriptional regulator even in the presence of EWSR1::FLI1, altering the expression of hundreds of genes, including the genes encoding the fibrillar collagen COL5A3 and the focal adhesion protein TNS3, suggesting that ETS1 could exert substantial phenotypic effects if expressed in tumor cells (Figs. 5 and 7).