Always stick around for the last question at a life sciences panel. In a discussion entitled “How to survive in 2012 and beyond,” at the CED Life Science Conference in Raleigh, four life sciences CEOs discussed everything from the rough terrain for later-stage investments in healthcare (“A C-round is not for the faint of heart”) and the myth of a “liquidity event” during an IPO (“60 to 70 percent of the money will come from insiders”).

Then as a throwaway last question they got this: What keeps you up at night?

The four CEOs — Neal Fowler of Liquidia Technologies, David Levison of CardioDx, Mark Sirgo of BioDelivery Sciences International (Nasdaq:BDSI) and Tim Willis of TearScience — gave four unique, useful and often inspirational answers.

The responses tell you both about the issues that confront life sciences executives today as well as the DNA of a successful startup CEO.

Here’s a paraphrase of what they said when asked: What keeps you up at night?

  • Neal Fowler, Liquidia

It’s about how to think creatively, about how to win in this market. This is the new normal. People keep talking about how things are going to change back. I don’t think they are going to change.

So, it’s creativity in my thinking. I love to read about other industries. There are parallels in the life science industry that we miss because we keep looking back at the old paradigm.

  • David Levison, CardioDx

It’s about what’s the next hurdle. Right now, the hurdle for CardioDX is can we get payers to pay for it? I like waking up in the middle of the night. There’s always another hurdle and another ridge to climb. There’s always, “What’s the next thing you have to do for the organization?”

  • Mark Sirgo, BioDelivery Sciences

Having enough time to think strategically. Sometimes you get so bogged down in the operational and we need to take time to think strategically. Times like this present the opportunity to reinvent these companies.

The other thing that keeps me up is that our company is virtual in nature. That keeps me up. Because we don’t have control over what goes on at the companies we work with.

  • Tim Willis, TearScience

I sleep like a baby. I am a cancer survivor. There is nothing that keeps me up at night.

But for the entrepreneurs, what you have to understand is that success is 1 percent idea and 99 percent perspiration. You have to have a passion — passion for the perspiration.

If there’s anything that would keep me up at night it’s when I sometimes lose that passion and worry about things I have no control over. What I have to do is understand what I can control. For the other things I say, “Lord that’s your problem. I’ll be there when you need me.”

I have several companies that I will start in the future. I don’t care what the environment is and how difficult it is.