The blood-testing company Theranos — until recently a Silicon Valley darling — lost its largest revenue source after Walgreens terminated the companies' relationship late Sunday. Walgreens cited problems federal regulators have had with Theranos' lab testing and potential sanctions over problems found at its labs.

Walgreens' withdrawal is another step in a rapid fall from grace for Theranos — and ends a partnership that was the cornerstone of its early success.

Investors in Bellevue-based drugstore.com gather Thursday for their annual shareholder meeting. It's likely the last time they'll meet there. 

The online-retailer is being acquired by its biggest brick and mortar competitor: Illinois-based Walgreens.