CCND1 and Ewing sarcoma: To further dissect the regulatory mechanism underlying CCND1 expression in Ewing sarcoma cells, we searched for molecules that induce transcription of pncCCND1_B. Herein, we report that etoposide treatment was able to upregulate pncCCND1_B expression and induce Sam68 re-localization to form a network hub on the CCND1 promoter, contributing to CCND1 downregulation.