It’s the employment law case everyone is watching. A massive, long-running gender pay discrimination class action against Walmart has overcome another hurdle on its way to what could become the largest payout to employees in U.S. history. The plaintiffs—potentially 1.5 million women who have worked at 3,400 Walmart stores—got a victory in April when the full panel 9th Circuit Court of Appeals gave the go-ahead for the case to proceed.