According to Business Insider, the round was led by SoftBank Group and included other investors that also had previously funded Guardant, such as Khosla Ventures and Sequoia Capital. In total, Guardant has raised more than $500 million.

Guardant makes a "liquid biopsy" test, called Guardant360, that uses blood samples from cancer patients and sequences the genetic information in that blood to figure out how tumors are responding to a certain cancer therapy. These tests rely on something called circulating tumor DNA, or the bits of DNA that dying tumor cells release into the bloodstream.

The new round will help fund Guardant's goal to sequence 1 million cancer patients over the next five years, which could help the company develop an early-detection test. Such a test would require a whole bunch of data that isn't readily available today.