The amount of a DNA-directed RNA polymerases I, II, and III subunit RPABC2 when measured in blood serum. The trait is Ontology of Biological Attributes id OBA_2042969 (level of DNA-directed RNA polymerases I, II, and III subunit RPABC2 in blood serum). Also known as: blood serum DNA-directed RNA polymerases I, II, and III subunit RPABC2 amount.