(CNN) Two months after jurors awarded a dying cancer patient $289 million, the judge is taking issue with that amount -- and might overrule a huge chunk of it.

Former school groundskeeper Dewayne Johnson won the landmark case against Monsanto, claiming the company's popular weedkiller Roundup caused his non-Hodgkin's lymphoma. Johnson is the first of more than 4,000 cancer patients to take Monsanto to trial.

The big questions at stake were whether Roundup can cause cancer and, if so, whether Monsanto failed to warn consumers about the product's cancer risk.

The jury sided with Johnson on both and awarded him $250 million in punitive damages (to punish Monsanto) and about $39 million in compensatory damages (for Johnson's lost income, pain and suffering).

But on Wednesday, San Francisco Superior Court Judge Suzanne Bolanos made a tentative ruling that could nix that $250 million punitive award and prompt a new trial.

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