Analysis of the relationship between CDO1 methylation abnormality of SBC tissue and clinicopathological factors revealed a positive correlation of the TaqMeth V with tumor diameter (R = 0.31) and a significant difference in CDO1 methylation was observed between groups with high and low tumor diameter when the cutoff value of the tumor diameter was 3.5 cm (p = 0.0002). The gene discussed is CDO1; the disease is neoplasm.