Cellular Dynamics International announced this week that it has filed with the SEC for an initial public offering of common stock.

The company founded by stem cell pioneer James Thomson develops stem cell technologies for in vitro use in drug discovery, toxicity testing and chemical safety.

Common stock shares cannot be sold or solicited until the SEC makes the company’s registration statement about the proposed IPO–filed on June 3–effective.

The number of shares offered and price of shares remain undetermined at this point. When shares open, the stock is expected to be listed under the symbol “ICEL” on the NASDAQ Global Market.