The blood tests known as liquid biopsies may soon be the alternative to invasive tumor biopsies. DNA fragments from mutated cancer cells can be found in the blood of people with cancerous tumors. At present liquid blood tests are used to monitor the progression of a disease and the effect of the drugs being administered. The data is the result of research done at the University of California Davis Comprehensive Cancer Center. One such test on the market (Guanant) detects 70 cancer-related genes. The study tested the accuracy of tumors removed from 400 patients against the DNA removed from taking a blood sample. The shortcoming is that 15% of those tested did not show the presence of cancer mutations where their actually was. Hope is that in the future patients may be spared the pain of invasive tumor biopsies.