Cluster 1568: hepatitis hbv virus positive hcv pcr antibody polymerase chain surface 
Cluster 2088: hepatitis pcr positive antibody polymerase chain antigen reaction surface core 
Cluster 2467: hepatitis polymerase chain reaction pcr positive active infection antiviral antigen 
Cluster 2494: methylation mgmt polymerase chain reaction pcr routinely status quantitative available