Circulating nucleic acids in plasma and serum: roles in diagnosis and prognosis in diabetes and cancer.

The presence of DNA and RNA circulating in human plasma and serum is described. The possible sources of the DNA/RNA in blood, their ability to enter other cells and to express in the recipient cells are discussed and the relationship with metastases considered. The possible role(s) of the DNA/RNA in clinical diagnosis, in monitoring treatment and in prognosis are considered for diabetes and oncology.