EWSR1 and Ewing sarcoma: For example, one of the FET proteins in Ewing sarcoma (EWS) depletion results in alternative splicing (AS) changes of genes involved in DNA repair and genotoxic stress signaling, including ABL1, CHK2, and MAP4K2. Chromatin and RNA crosslinking immunoprecipitation experiments show that EWS co-transcriptionally binds to its target RNAs.