If successful, it'll be awfully difficult for any other lawsuits to proceed.
The first crop of those lawsuits went to trial this year (it's fun to look back at the end of the year!), and have not gone well for the agrochemical giant; courts have awarded settlements in the tens of millions of dollars against Monsanto. But Monsanto this week asked for something unusual, a Hail Mary that, if successful, might negate all of those pending lawsuits.
Roundup is the brand name for a broad-spectrum herbicide called glyphosate. Ronudup is hugely successful, used everywhere from backyard gardes to thousand-acre monocrop operations, but it's been repeatedly linked to cancer, most importantly in a World Health Organization 2015 classification.
Monsanto has vigorously argued that the link is inconclusive, and that's sort of true, though much or the research saying it's not a carbinogen was funded by Monsanto itself.