Bill Gates is known for his philanthropic contributions to health, education, and anti-poverty organizations through the Bill and Melinda Gates Foundation.

But the billionaire founder of Microsoft has also made a number of more under-the-radar personal investments.

From fake meat to blood tests that could detect cancer early, take a look at a few Silicon Valley initiatives that Gates has supported in the past decade.

Grail, a startup aiming to detect cancer when it's still curable.

Grail, a startup aiming to detect cancer when it's still curable.

Getty Images

Founded in 2016, Grail is a life sciences company working to develop technology that could spot cancer before it's incurable. Grail says on its sitethat it believes a special type of blood screen could be the key.

Grail was funded in 2016 by its former parent company (the gene-sequencing giant Illumina) and a group of high-profile investors including Gates, Jeff Bezos, and Google Ventures. The Series A round totaled $100 million, and Grail has garnered $1.2 billion in investments to date.

EtaGen, a startup developing highly-efficient power generators.

EtaGen, a startup developing highly-efficient power generators.EtaGen

EtaGen is a startup producing ultra-efficient generators that supply power for companies, buildings, and microgrids. In 2012, CEO Shannon Miller toldMIT Tech Review that EtaGen's engines use on average 25% less fuel (like natural gas or diesel) than traditional gas-powered generators.

Founded in 2010, the company has raised $133 million to date. Bill Gates and others invested $83 million in a Series C funding round in early 2018., a company publishing online petitions., a company publishing online

With over 150 million users in 196 countries, is a popular site where people can start petitions for specific causes. Current US-based petitions include one tostrengthen gun laws and onesupporting farmworkers' rights.

In a Series C funding round in received $30 million from Gates and others. The company has raised $83 million to date.

Varentec, a startup creating products that help citywide electric grid systems work more efficiently.

Varentec, a startup creating products that help citywide electric grid systems work more efficiently.Getty Images

Founded in 2002, Varentec develops products for electrical grid systems, including a software platform that lets cities more easily manage how power flows. The startup claims that its devices can help utility operators reduce wasted voltage, manage peak power demands, and avoid overloading circuits.

Gates participated in two separate funding rounds in 2014 and 2015. To date, the company has attracted $41.9 million in venture capital.

Impossible Foods, a startup producing plant-based "meat."

Impossible Foods, a startup producing plant-based

The Impossible Burger.  Impossible Foods

Since its founding in 2011, Impossible Foods has been on a mission to engineer plant-based "meat" that tastes like the real thing. The meat-like flavor largely comes from an ingredient called heme, which allows the Impossible Burger to "bleed" like a beef burger.

In April, the food-tech startupdebuted its sliders at 140 White Castle locations across New York, New Jersey, and Illinois, and its burger is now available at over 1,400 restaurants nationwide.

Impossible Foods has raised an estimated $387.5 million to date, with Bill Gates participating in three funding rounds that totaled $208 million from 2013 to 2017.

Gates has also invested in another plant-based food startup, headquartered in Los Angeles, called Beyond Meat in 2015. The Series E funding round totaled $17 million.

Memphis Meats, a startup growing "chicken," "duck," and "beef" from animal cells in a lab

Memphis Meats, a startup growing

Uma Valeti and Chef Derek Sarno present meals by Memphis Meats. Memphis Meats/Facebook

Memphis Meats has a similar goal to Impossible Foods, but it's aiming to achieve it in a different way. Instead of relying on plant-based ingredients, the company is working to cultivate meat from animal cells in a lab. So far, Memphis Meats has made lab-grown chicken strips, lab-grown meatballs, and lab-grown duck.

The team previously told Business Insider that it expects to reduce production costs over the next few years, and start offering its products to the public in 2021.

In 2017, Gates participated in a $17 million Series A funding round.

This post originally appeared on Business Insider.