The maker of Roundup weed killer is lobbying state and federal lawmakers to block cancer victims from suing the company for not properly disclosing the herbicide’s alleged health risks. Last year, the company (which acquired Monsanto in 2018) helped write versions of a “Cancer Gag Act” introduced in Idaho, Iowa, and Missouri — and briefly featured in a federal farm bill draft — that shield chemical makers from “failure-to-warn” lawsuits if they comply with the EPA’s labeling standards.