As another week in biotech comes to a close, I've got a fresh batch of tweets that were entertaining and educational. As a reminder, if you've got a tweet you think is worthy of this weekly column, send me a link @BiologyFool.

The line between big pharma and big biotech is becoming increasingly blurry. Gilead Sciences (NASDAQ:GILD), traditionally called a biotech even though most of its drugs are small molecules, went over the $100 million market cap threshold this month.

Gilead's recent success can be attributed to its diversification away from its HIV program. Those drugs are still providing a majority of the cash flow, but investors no longer have to worry about the eventual demise of the program to generic competition. Gilead can count on its hepatitis C and oncology programs to be the next big thing.

Gilead is the size of a pharma because it's looking more and more like one with every in-licensed drug, and positive clinical trial.

Biotech IPOs have been on fire lately, but initial public offerings in this sector aren't exits for the venture capitalist that invested in the private companies. When they IPO, biotechs sell new shares to raise additional capital. Bruce estimates that VCs still own about 60% of the shares in the recent IPOs.

The big fear is that insiders will rush to the exit to get out after the lockup period ends to capitalize on their unrealized gains. Bruce offers a few ways start-ups can keep that from happening. If you're invested in a recent IPO, it's a must read. (And it's insightful, even if you're not.)

Smart investors get a variety of opinions when making investment decisions. Apparently, that goes for companies, as well.

Last month, PDL Biopharma (NASDAQ:PDLI) paid Depomed (NASDAQ:ASRT) $240 million in exchange for royalties Depomed receives from six different drugmakers. Clearly, that's only a good investment if PDL Biopharma can recoup its initial investment quickly. It makes sense to get independent opinions of Depomed's future royalty estimates from analysts like Jason. Apparently, it was a good reference if they downloaded it six times.

Vertex Pharmaceuticals (NASDAQ:VRTX) fell this week after announcing that sales of its hepatitis C drug Incivek are on a steep decline. Patients and their doctors are increasingly waiting for the next-generation drugs from Gilead Sciences and Johnson & Johnson that are on the horizon.

Of course, long-term investors were holding Vertex for its cystic fibrosis program rather than its prospects in hepatitis C. The decline might have been steeper than people would have expected, but Vertex's long-term prospects in cystic fibrosis haven't changed. Vertex's drug combinations have the potential to treat the underlying cause of the disease, while current treatments only treat the symptoms.

Brad's advice to look for companies that will have the biggest impact on patients is good strategy for biotech investors. I'd throw Sarepta Therapeutics (NASDAQ:SRPT) out there as another example. Its revolutionary Duchenne muscular dystrophy drug, eteplirsen, treats a disease where patients currently have no options. In the short term, there's doubt over whether the FDA will approve eteplirsen based on the limited data. But over the longer term, it seems extremely likely that Sarepta Therapeutics can eventually get the drug approved after running a larger trial.

I think @BsiflingTrades might have the right idea with Sarepta: