Ontology of Biological Attributes identifier OBA_2044686 (level of carboxy-terminal domain RNA polymerase II polypeptide A small phosphatase 1 in blood serum) is the amount of a carboxy-terminal domain RNA polymerase II polypeptide A small phosphatase 1 when measured in blood serum. Also known as: blood serum carboxy-terminal domain RNA polymerase II polypeptide A small phosphatase 1 amount.