A few weeks ago, Priscilla Chan and Mark Zuckerberg made an astounding announcement: a $3 billion investment towards curing all diseases within a century. Dr. Chan declared they want to improve the lives of everyone in their daughter's generation, and not "miss a single soul." To start this admirable endeavor, it was announced that the first tranche of funding will go towards a Biohub bringing together researchers from the greater Bay Area.

This is a great start. But if they really want to cure all diseases for all people, Chan and Zuckerberg should invest in research and medicine beyond the high-profile institutions in their backyard. Way beyond.

There are thousands of scientists in the developing world who have spent decades toiling against the diseases that affect the majority of humanity. They are on the front lines of longstanding culprits like malaria, which affects millions each year, and urgent outbreaks like Ebola and Zika.

They also have unique avenues for finding such solutions. These include a treasure-trove of medicinal plants that have been used to treat every kind of human ailment for millennia. At Kenyatta University just outside Nairobi, a Masters' student showed me his thesis listing every medicinal plant used by a single tribe in central Kenya. He had detailed which part of each plant was used for each specific physical indication; the list ran for at least 20 pages.

Over the last eight years, I have met dozens of scientists from around the world mining plants and other natural resources for new medicines. They are looking for new antibiotics in the soil of Namibia, the soda lakes of Kenya, and the urban wastewater of Jamaica.

But they are hamstrung by highly constrained research environments and limited access to research funding. While a typical NIH grant for a US scientist can be hundreds of thousands of dollars, typical grants for developing world scientists may be capped at $15,000 and they may come with restrictions on how the money is spent.

In a survey we recently conducted of African scientists and engineers, 64 percent reported that their grants did not allow them to purchase lab equipment. Many of the scientists I meet are in fact paying for chemicals, equipment, and even student stipends from their own pockets.

With insufficient funds for advanced equipment, research projects stagnate and are often downgraded to a narrower scope. This makes it far less likely for the work to be published in mainstream journals, making the results almost invisible to potential colleagues elsewhere in the world. Funding constraints also prevent many scientists from the developing world from attending international conferences where they could share their discoveries or meet potential collaborators and funders.

Despite these constraints, they push forward, even as far as patenting discoveries in nutrition and health. But with few avenues to showcase their work to investors, these solutions rarely reach the markets that need them so desperately.

Every one of these barriers is solvable.

Increasing funding for the basics—equipment, chemicals, travel, and stipends—is the first step. By ensuring scientists in the developing world have these tools, we also ensure they are no longer second-class members of international consortia. Fostering more connections for them with their counterparts in the US then becomes a matter of two-way knowledge sharing and the potential for fruitful and productive collaborations.

As an example, we were part of a collaboration with U.S.-based researchers, a U.K. software company, and Canadian funders to help the University of Nairobi Chemistry Department digitize the structures of hundreds of molecules they have isolated over three decades of research. They have now put these online in the first-ever open-source database of medicinal compounds from an African institution.

As the Nairobi chemists point out, the first anti-malarial compound, quinine, came from a South American plant and the latest, artemisinin, grew from traditional Chinese medicine. Resistance is growing to both of these drugs. Surely, these chemists say, the next anti-malarial will come from Africa where the disease is also endemic. Perhaps it is lurking in their database right now.

If I had $3 billion to invest in curing the world's diseases, that is where I would start.