Doctors have said they didn't expect him to live to see this day. But Monday marks a milestone: Johnson, 46, is the first of hundreds of cancer patients to see his case against agrochemical giant Monsanto go to trial.
Johnson, a former school groundskeeper, regularly used Roundup and claims it gave him cancer.
CNN reported last year that more than 800 patients were suing Monsanto, claiming its popular weed killer, Roundup, gave them cancer.
Since then, hundreds more non-Hodgkin's lymphoma patients have made similar claims, Johnson's attorney, Timothy Litzenburg, said. He now represents "more than 2,000 non-Hodgkin's lymphoma sufferers who used Roundup extensively," he said.
Johnson, a father of two in California's Bay Area, applied Roundup weed killer 20 to 30 times per year while working as a pest manager for a county school system, his attorney said.