SAN FRANCISCO (KPIX 5) — The corporate world was closely watching a legal battle in a San Francisco court Tuesday.

In a case of “David vs. Goliath,” private citizen Lee Johnson is suing chemical giant Monsanto. Closing arguments were made in court Tuesday afternoon. Now the case is in the hands of the jury.

Johnson, 46, is suing the multi-billion dollar corporation for failing to warn him about the dangers of using Ranger Pro — the bulk version of Roundup, the company’s weed-killing chemical product — during his work as a groundskeeper for the Benicia Unified School District.

Johnson is dying of non-Hodgkin’s lymphoma and said that Monsanto is to blame.

Lawyers on both sides came out swinging in court.

Johnson’s attorneys went so far as to show the jury how to fill out a verdict form, asking Monsanto Corporation to pay $373 million in punitive damages, with $39 million being awarded to Johnson.

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George Lombardi, the lead defense attorney for Monsanto, spent the afternoon trying to discredit every doctor and study that Johnson’s lawyers cited throughout the trial.

“It would be nice to give cancer patients some idea of why they were the unlucky ones. The truth is, you frequently just can’t do that,” said Lombardi.

“You have to look at what the actual facts are. There’s facts and there’s arguments. The facts are what should lead you in this case,” he added.

From the beginning, this case has been a battle over which science the jury should choose to believe.

Johnson’s lawyers said the main chemical in Roundup clearly causes cancer, while Monsanto argued that the link between the chemical and the disease simply can’t be established.

One thing is clear: if the jury sides with Johnson, thousands of other cancer patients with similar cases are lined up, hoping to take on the corporate giant as well.

“When you return a verdict, we’re going to make it right. Your verdict will be heard around the world. Monsanto will finally have to do something,” declared Brent Wisner, one of Johnson’s attorneys, to the jury.

The case was expedited because of Johnson’s poor health. He’s expected to enter another round of chemotherapy in the coming weeks. Deliberation of the case will begin on the morning of Aug. 8.