We identified 72 shared small eccDNA‐associated genes between cancer plasma and cancer tissues, including some cancer‐related genes, such as ALK receptor tyrosine kinase (ALK), ETS transcription factor ERG (ERG), ETS variant transcription factor 6 (ETV6) and casein kinase 2 alpha 3 (CSNK2A3).39 The gene discussed is CSNK2A3; the disease is cancer.