When Democratic House Minority Leader Nancy Pelosi was asked today for comment about MIT professor Jonathan Gruber's recent remarks that "lack of transparency" and "the stupidity of the American voter" were critical to helping pass Obamacare, she responded briskly: "I don't know who he is. He didn't help write our bill." 
Watch the complete video of her denial at the end of the post, via C-SPAN
Pelosi's remarks are easy enough to check. And she appears to be wrong on both statements.
Did Gruber help write the Affordable Care Act? According to a 2012 article in The New York Times, he did: 
After Mr. Gruber helped the administration put together the basic principles of the proposal, the White House lent him to Capitol Hill to help Congressional staff members draft the specifics of the legislation.
As for whether Pelosi's claim to not know who he is, well, she knew who he was November of 2009, and said so at a press conference.
The Washington Post dug up a transcript of Pelosi citing Gruber's work by name in support of Obamacare. Here's the relevant section: 
Q: As you know, the Republicans released their health- care bill this week. And I wanted to get your comment on the bill, and specifically on the CBO analysis that it would cost significantly less than the Democratic plan and that it would lower premiums.
PELOSI: Let me just say this. Anything you need to know about the difference between the Democratic bill and the Republican bill is that the Republicans do not end the health insurance companies' discrimination against people with preexisting conditions. They let that stand. That's scandalous, the fact that it exists. I don't understand why they have not heard the American people, who have said preexisting conditions should not be a source of discrimination.
And secondly, the Republican plan ensures about 3 million more people than now, and ours does 36 million people. So that's a very big difference in that.
We're not finished getting all of our reports back from CBO, but we'll have a side by side to compare. But our bill brings down rates. I don't know if you have seen Jonathan Gruber of MIT's analysis of what the comparison is to the status quo versus what will happen in our bill for those who seek insurance within the exchange.  [emphasis added]
Those remarks are also on video. Watch below.
In addition, Pelosi's office touted Gruber's analysis of the law's premiums on the House Speaker's website. For that matter, so did the White House. There's just no question that Gruber was closely involved with the creation of the law, and widely cited as an authority on how it would work. 
In attempting to deny any connection between herself and Gruber, or between Gruber and the law, in order to shrug off Gruber's claim that "lack of transparency" was key to passing Obamacare, Pelosi ended up inadvertently proving Gruber's essential point: In making the case for Obamacare, supporters of the law have not been transparent with the public.
And here's the video from 2009: