Could we soon have a simple blood test for all cancers? A test that is able to detect every form of cancer through a DNA blood screening, long before any symptoms arise?

Before you write that idea off as a foolhardy quest similar to the hunt for the Holy Grail, you should know that llumina (NASDAQ:ILMN), the company that brought us effective, cheap sequencing of DNA, hopes to roll out exactly such a test by 2019.

The cost is projected to be around $500 a person. And, while skeptics abound, so do true believers, including two ace biotech investors, Jeff Bezos and Bill Gates, who you no doubt know as the founder of Amazon (NASDAQ:AMZN) and co-founder of Microsoft (NASDAQ:MSFT), respectively.

In biotech, the "Gates-backed" or "Bezos-backed" stamp carries huge clout

Jeff Bezos and Bill Gates led the $100 million round of Series A funding for the Illumina spinoff formed to create the all-in-one liquid cancer biopsy. Illumina has dubbed the new company Grail and will retain majority ownership.

It's a bit of a departure from the norm for these two tech titans, although Gates has a growing portfolio of venture investments in cancer treatment, including companies such as Nimbus Discovery and Foundation Medicine. Bezos has similarly invested in cancer treatment, most notably through Juno Therapeutics, a publicly traded  small-cap working on breakthrough immunotherapy treatments.

But Grail's focus is on something much more foundational than improving cancer treatment. The goal is to win the war against cancer. In the real world of cancer treatment, the disease is often detected too late, when a cure is impossible -- and treatment is often completely ineffective.

By contrast, Grail's test keys in on the relatively recent discovery that genetic material from cancer circulates in the blood. Finding circulating tumor DNA (ctDNA) can indicate a tumor is forming long before it has a chance to spread.

The upshot? Cancer will be found earlier, when it is more likely to be treatable, which should massively decrease the world's cancer mortality.

But will the test work?

Gates and Bezos no doubt know they are entering a minefield.

Catching cancer early is an incredible challenge. "If you look at this business, it's littered with failures." Illumina's current CEO Jay Flatley said in an interview with the MIT Technology Review. "With a few exceptions, screening tests have been invariably horrible."  

But efforts by other companies have been criticized for having too little research behind them. Grail has an advantage in Illumina's status as the dominant manufacturer of gene-sequencing equipment. Illumina's machines generate 90% of all DNA sequence data today, and the company is increasingly moving toward developing consumer genetic tests with efforts like Grail.

That two-pronged business strategy makes excellent sense. As the technology moves forward, Illumina has a shot at both owning the hardware that keeps making DNA sequencing cheaper (so genetic tests become more accessible), and then selling all the tests.

In other words, it's positioning itself for world domination.

Potential payoff? A cool $20-$200 billion

Illumina's first test (due in 2019) will focus on Stage 2 cancers, which the company claims is a $20 billion to $40 billion opportunity. A Stage 1 cancer screening should follow, which could unlock an overall market of $100 billion to $200 billion.

Leerink analysts are on board with these numbers. They predict an eventual market reaching between $20 billion to $200 billion for Grail.

Still, while scientists will be working furiously to make the test a reality, it doesn't mean they will succeed. And the FDA will have a say. Notably, an earlier effort by another company, Pathway Genomics, to create a pan-cancer blood test was greeted last September by a stern letter. The FDA told Pathway there was no "published evidence that this test or any similar test had been clinically validated as a screening tool for early detection of cancer."

Genetic cloud-based big data solutions from Microsoft/Amazon

What about Microsoft and Amazon investors? Both Bezos and Gates invested personally, there's no direct company involvement, but Illumina already has a history of integrated product relationships with Microsoft and Amazon in cloud-based storage and big data solutions. With the huge amount of data-crunching and analysis needed to develop consumer genetic tests, it could go much further. To give you a perspective, the amount of DNA sequencing required to fully research Grail's test has been estimated as the equivalent of decoding the genomes of about 400,000 people. That makes this project about three times as large as Genomics England, a national effort to study cancer and disease in the U.K.

Beyond that, as the field evolves, it should expand beyond researchers who need DNA sequencing, to clinicians and consumers who might want it. In fact, it's highly possible a DNA sequencer will become a cloud-based node in the Internet of Things, with subscription software, for both control and processing.

Key in on a few of those words -- cloud-based node, Internet of Things, subscription software -- and you'll understand the opportunities kicking around for big moneymakers like Amazon and Microsoft. No wonder their founders are so keenly interested.

Time to buy Illumina stock? Be patient.

One of Jeff Bezos' rules for success is: Be patient. Small investors will need to emulate that patience as Illumina undertakes this new venture. Don't expect a stock pop. In fact, Grail will result in a hit to earnings this year, although Jay Flatley, who will serve as chairman of Grail, will not say how much at this point.

Still, the opportunity to leverage genomic data into cancer detection is right on target with healthcare's move toward personalized medicine. If Illumina can pull this off and prove Bezos and Gates right, investors should find themselves ecstatic with this stock a few years from now.

Just... be patient.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.