Opening statements could begin as early as today for the trial of a California man suing herbicide Roundup maker Monsanto, which he believes caused him to get cancer through its weed killer.

Dewayne “Lee” Johnson, a 46-year-old father of three, says he became sick after using the spray for more than two years as a groundskeeper for a school district outside San Francisco.

Roundup’s main ingredient, glyphosate, has been linked to controversial reports since its debut in the late 1970s. In 2015, the World Health Organization classified glyphosate as “probably carcinogenic to humans.” Monsanto has adamantly denied the claims.

Johnson is the first of a long-list of about 4,000 people looking to sue the weed and seed maker for similar allegations.

While Timothy Litzenburg, Johnson’s lawyer, who also represents hundreds of other victims, and Monsanto agreed they will not speak to the media until a jury has been empaneled, he told FOX Business back in 2017 cases of Non-Hodgkin’s lymphoma (NHL), a type of cancer, have been directly linked to the uptick of Roundup use.

Christine Sheppard, a 68-year-old retired coffee-bean farmer, who is represented by Litzenburg and plans to take her case against Monsanto to trial after Johnson, tells FOX Business she believes she contracted cancer from her years of using Roundup, too.

“When I was first diagnosed, I thought, ‘Why me? What did I do?’ And then when I saw those reports about Roundup being linked to cancer, it all clicked into place,” Sheppard says.

“[Monsanto] did exactly what the tobacco industry did. They hid reports linking its weed killer to cancer,” she adds.

Sheppard, whose cancer is in remission, says she wanted to sue because she wants Roundup to be banned and taken off store shelves. “I still see it at my local stores. Roundup has destroyed my life and has caused my family so much pain,” she says.

Carey Gillam, an investigative journalist and author of a new book, Whitewash, that details Monsanto’s history with this chemical and the revelations found in the company’s internal records, tells FOX Business Johnson’s case will shine a public spotlight on Monsanto’s attempt to cover up studies linking the chemical with the disease. “The plaintiff is not only alleging exposure to Roundup caused his cancer, but that Monsanto has long known about the dangers of its product and has suppressed and manipulated the science to hide the dangers from the public,” Gillam says.

She says with the more than 4,000 other plaintiffs waiting in the wings, if the jury sides with Johnson, this litigation has the potential to last for decades and cost Monsanto and its new owner, Bayer, hundreds of millions – if not billions – of dollars in damages.