Detection of circulating methylated BCAT1/IKZF1 DNA is associated with primary CRC; the biomarkers disappear following adequate CRC treatment; their detection during surveillance is indicative of CRC recurrence for which we have previously reported a 63–68% sensitivity and 92–98% specificity; and the ctDNA test is more sensitive than CEA testing.27, 29, 30, 31, 32, 33, 34. The gene discussed is IKZF1; the disease is colorectal carcinoma.