$4 million. The $2.5million will be for the warrants at $2/sh.
The buyer gets a great option at $2. The company gets cash now and more letter with a rising tide. They also get more confidence with negotiations with a potential partnership. The partner may have thought that they had CUR by the short hairs, but this should move the dial back in CUR's favor as they should not be desperate to make a quick/bad deal.