Today at 9:00 am, Pershing Square's Bill Ackman will be the latest to hold a call defending not only Valeant, but his massive 22 million share stake in the company. He will have a lot to talk about, especially in the aftermath of overnight's whirlwind of negative news surrounding Valeant, which prompted the company to unexpectedly sever ties with the specialty pharmacy at the center of it all, Philidor. Here is how the WSJ, which will live blog the event, describes it: The pharmaceutical company has been in the center of a host of questions about its business practices, its accounting practices and its relationship with mail-order pharmacy Philidor Rx Services, LLC. On Friday, Valeant said it is severing all ties with Philidor, which will shut down operations as soon as possible. Valeant’s decision came on the heels of news Thursday that the three largest pharmacy-benefit managers in the U.S. said they are ceasing work with Philidor. Separately, two board members of a large Valeant investor, Sequoia Fund Inc., resigned. Mr. Ackma has told investors over the past week he believes that Valeant is vastly undervalued and that some of the criticism of its dealings is unwarranted, people familiar with the matter have told the Wall Street Journal. Last year, Mr. Ackman teamed up with Valeant in its attempts to buy Allergan, which was ultimately unsuccessful. During that pursuit, Mr. Ackman joined Valeant Chief Executive Michael Pearson on severals calls to persuade Allergan shareholders to accept Valeant’s offer. Needless to say, for Ackman who has generated over $2 billion in paper losses in VRX since its recent peak, this may be a matter of professional life and death. And just to tip the scales to the latter, Ackman's nemesis Herbalife, issued the following press release moments ago: “I hope Bill Ackman has done more research on Valeant than he did on Herbalife, Target, Borders and JC Penny,” said Alan Hoffman, executive vice president, global corporate affairs, Herbalife. Those who wish to follow the call, can do so here or telephonically: US Toll-Free Participant Event Plus Dial-In Number: (844) 489-4527Participant International Dial-In Number: (925) 418-7826Conference ID 69916104 Questions for the call should be emailed to ir@persq.com. The webcast is below