In addition, the coincidence rate of altered genes EGFR, DICER1, FLT3, CDKN2A, PIK3C2G, KRAS, IDH1 and ATM between pericardial effusion-cfDNA and pericardial effusion-sDNA ranged from 50% (50% included) to 100%. The gene discussed is CDKN2A; the disease is pericardial effusion.