We found that KDM6B promoter DNA hypomethylation (CpG site from 2 to 7) was enriched in MCPyV-positive MCCs (Fig. 7A, B) and correlates with KDM6B overexpression in MCC (Additional file 2: Table S2 and S3). The gene discussed is KDM6B; the disease is Merkel cell skin cancer.