(CNN) Leslie Paul is living out her childhood dream of being a scientist, but the cancer researcher is worried her lab's funding may dry up under the Trump administration.

The 36-year-old is part of a lab that works to cure aggressive melanoma, as well as a blood cancer called multiple myeloma. More than 70% of the funding for her lab at the Roswell Park Cancer Institute in Buffalo comes from the National Institutes of Health or its member agencies.

President Trump's budget proposal , unveiled in March, outlined $54 billion in cuts across government programs to make way for an increase in defense spending

If Trump's proposed $5.8 billion budget cut to the NIH happens, who knows what will happen to the work Paul's lab is doing.

That's why she is marching -- for the first time ever -- in Saturday's March for Science in Washington DC.

"We're all really, really scared just based on the initial desire to cut NIH funding," she told CNN. "In terms of us, NIH is everything and so is the National Cancer Institute."

The funding for her lab goes toward paying salaries, buying the reagents to run experiments -- some of those reagents cost $500 per milliliter, she said -- and keeping the lights on at the institution.

It's not so much me being out of a job. It's taking away the hope for the patient and that's disgusting." Leslie Paul, cancer researcher

"It's not so much me being out of a job. It's taking away the hope for the patient and that's disgusting," she said.

Beyond the research woes, for Paul, it's about sending a message that science will not be silenced.

"Even if funding for NIH weren't specifically affected, this is about sending a message together as scientists, science enthusiasts or even people who support science," she said.

"If there was ever a time that it was important to say, 'You can't do that to the EPA, you can't disregard wildlife, you can't censor science,' it would be now."

For each, a different reason

Rachel Golden Kroner

There are a lot of reasons scientists, educators, parents and supporters will march

For conservation scientist Rachel Golden Kroner, she's marching not only for science, but for people that depend on science, which is all of us.

"If we do nothing, we face a crisis for biodiversity and people," she said. "Extreme weather events will be the norm, sea level rise will force people to migrate, diseases with certain vectors will spread to more people; the list goes on and on."

What science stands to lose

It's not just Washington. Organizers say more than 500 satellite marches are planned for Saturday -- across the US and around the world.

"I think there has been a declining sense of what science means to progress. I think we take so much for granted," said march honorary co-chair Dr. Lydia Villa-Komaroff.

Villa-Komaroff rattled off a list of things she's most worried about if research dollars are cut:

The environment. Public health. Food safety.

We need agencies like the EPA, the NIH and the Department of Agriculture to keep us safe, she said. These agencies need ongoing research to do so. And for that, they depend on constant funding.

If funds are cut off or curtailed without planning, it can lead to a chain reaction: The scientists in the lab wouldn't be able to get what they need to do their work and their publicly funded universities would be losing a revenue source, Villa-Komaroff said.

"The draconian cuts would destroy work that's ongoing. The next generation says, 'Why would I go into research when there is no support?'" she said.

The march may have started because of politics, but it's bigger than that, Villa-Komaroff said. It's no longer just a public display of dissatisfaction over Trump's proposed budget cuts and the executive order cutting down on the EPA's climate change enforcement.

"It might have been ignited by Trump, but it's not about Trump," Villa-Komaroff said. "It's about the importance of science in society and continuing the support for the science community in keeping our edge."

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Talented scientists, gone

There's another thing that worries them, researchers say.

If you don't invest in science, you lose scientists. You lose scientists and you lose the ability to innovate.

The US draws researchers from all over the world. But between funding woes and travel ban restrictions , there's a palpable fear in the science community that the US will lose out on talented scientists.

Paul works on trying to figure out how melanoma spreads to other parts of the body.

On any given day, Paul, the cancer researcher, hears several different languages spoken on her floor: like Russian, Hindi, Mandarin. Some of her colleagues are from Iran, a place affected by Trump's travel ban

"I hear my colleagues telling me about how scared they are about not being able to stay here and do their job," she said. "That shouldn't affect the science."

Paul isn't sure if the march will change anything. But she's hoping for strength in numbers.

"Hopefully it sends a very powerful message to the legislative branch: This is very important; this matters and we vote," she said. "I hope that they see that science is important and we're not going to be silent. We're going to keep fighting."