(AP) — Regulators in California took a pivotal step on Monday toward becoming the first state to require the popular weed killer Roundup to come with a label warning that it's known to cause cancer. Monsanto, the chemical's maker, has filed an appeal after losing in court to block the labeling, arguing that Roundup doesn't cause cancer and that the labels will harm the company's business. Scott Partridge, Monsanto's vice president of global strategy, said in a statement that glyphosate does not cause cancer and there's no need to list it as harmful in California.