Sullivan spoke on Wednesday to two entrepreneurs, Kevin Gorman, CEO of Neurocrine Biosciences, and Jack Lief, president, CEO and co-founder of Arena Pharmaceuticals, both of whom could not be more positive about the biotech industry in San Diego.
Lief pointed to Arena's weight management drug Belviq, which the FDA approved in June.
Belviq is competing against the anti-obesity drug Qsymia, which is also available. Lief isn't bothered by that. "No single drug is sufficient for all indications, so I think the market is quite large," he said. "Obesity or people who are overweight account for about half of the adult population, so I think we'll have a very, very good opportunity," Lief said.
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To better market Belviq, Arena has partnered with Eisai, the Japanese company best known for producing Aricept, the $2 billion Alzheimer's drug still used today, and gastrointestinal drug Aciphex.
"They have about 10 drugs that they've been successful with, and we look forward to Belviq being quite successful, too," Lief said.
Neurocrine's Gorman said that diversifying risk is optimum for the neuroscience company, such as partnering with another company for clinical trials while spearheading other medical products simultaneously.
He added that investors should be confident. "The name of the game in this industry is adapt," he said. "Whether you're talking about regulators, or talking about the marketplace or payers, so you just have to adapt."
San Diego's business sector isn't limited to biotech, of course. Among its established businesses is the iconic WD-40, which was invented there 60 years ago and still retains its secret formula.
"We're now in 187 countries around the world, so we touch everybody," President and CEO Garry Ridge said.
Next up for Opportunity USA Road Trip: a visit to Minneapolis.
— Follow Brian Sullivan on Twitter @SullyCNBC.