Cell spiking assay and RT‐PCR were performed with blood samples from healthy volunteers spiked with six CRC cell lines to generate an algorithm, herein called the Six‐gene Assay, based on six genes (CEA, EpCAM, CK19,MUC1,EGFR and C‐Met) for CTC detection. The gene discussed is MUC1; the disease is colorectal carcinoma.