Take-Two Interactive chairman and CEO Strauss Zelnick has revealed that BioShock Infinite has sold more than 4 million units since its release last March. This comes hot on the heels of the first-person shooter's new DLC and the announcement of an impending return to more nostalgic, sub-aquatic pastures.

"BioShock Infinite is North America's best-selling multiplatform release so far this year, according to NPD," Zelnick said during an investor conference call following the release of Take-Two's financial results for the first quarter of its fiscal 2014. "The title has crossed the 4 million units selling mark, and we expect it to become the top-selling release in the BioShock franchise."