Here, we report for the first time that EBNA1 is a prion‐like protein, verified using cell‐based assays and the Saccharomyces cerevisiae Sup35p prion identification system.[21] In addition, we identified that EBNA1 interacts with the splicing factor SRSF1 to regulate the expression of the SRRM1 splicing isoforms, thereby promoting EBV‐associated tumor development. The gene discussed is SRRM1; the disease is neoplasm.