Liquid gold.

As in, liquid biopsies. Circulating tumor DNA has been the subject of biomedical lunchroom conversation for years. But it was trending in a major way at ASCO this weekend and is now garnering interest from billionaire investors. Early reports indicate this blood test can be used to effectively screen and risk-stratify notoriously ambiguous presenters of lung, pancreatic and prostate cancers. Results are promising, but both oncologists and investors alike are wise to remember: all that glitters isn't liquid gold.