Welcome to Law.com Class Actions: Critical Mass, a weekly briefing for class action and mass tort attorneys. 

This week: Another Roundup trial began Tuesday near Monsanto's headquarters in St. Louis. On Monday, a second phase of a San Francisco's opioid trial is set to begin on how much Walgreens must pay in abatement funds. Find out who represents Samsung Electronics America Inc. in lawsuits over its data breach.

I'm Amanda Bronstad. Feel free to reach out to me with your input. My email is [email protected], or follow me on Twitter: @abronstadlaw.