We're back yet again with three of the most humongous health-care stocks for the past week. Here are your weekly winners.

Mojo for Sangamo
Sangamo Biosciences (SGMO 0.47%) shot up 29% this week. There were no obvious catalysts this week for the surge. These nice gains appear to be because of a carryover effect from Sangamo CEO Edward Lanphier's presentation at the JPMorgan Healthcare Conference last week. 

Lanphier painted an encouraging picture for Sangamo's prospects. The company focuses on actually modifying genes to not just prevent or minimize the effects of disease, but rather to cure the disease. While Sangamo has studies under way for several diseases, it is farthest along with research on HIV/AIDS. 

Some investors could be eyeing Sangamo's partnership with Shire (NASDAQ: SHPG) with the thought that the larger company could ultimately acquire its smaller-but-promising ally. Others could be anticipating much loftier share prices in the near future after Sangamo announces phase 2 results from its HIV studies.  Regardless, Sangamo definitely has some mojo going on right now.

Life goes on... sale
Life Technologies (NASDAQ: LIFE) shares spiked nearly 13% this week. Most of the jump came on Friday following an announcement that the company is looking for a buyer.

The company's board is bringing in Deutsche Bank Securities and Moelis & Company LLC to "assist in its annual strategic review." In Wall Street speak, that means "we're for sale." Of course, the rumor mill will now kick into high gear over who might want to buy Life Technologies.

Several private equity firms have been mentioned as initial prospects for Deutsche and Moelis as they help with that annual strategic review stuff. Other competitors in the life sciences market with deep pockets are also possibly in the running.

Expanding
Shareholders in Opko Health (OPK) celebrated two expansions this week. The stock for the pharmaceutical and diagnostics company expanded as well, rising 12% over the past five days. Shares have been on a steady rise since December.

Opko kicked off the week with an announcement that it was expanding its relationship with Bristol-Myers Squibb (BMY 0.35%). The two companies first began working together in 2010 on research of Opko's technology in diagnosing Alzheimer's disease. Bristol and Opko plan to continue that research but will now also expand to other therapeutic areas.

The other good expansion relates to insider buying. Opko's CEO and chairman, Phillip Frost, bought 55,000 shares over the past week and has purchased nearly $1.5 million worth of stock so far in 2013. That's on top of a consistent buying each and every month going back to at least early 2011.

Humongously humongous
All three of these companies present intriguing stories for health-care investors. We Foolish investors tend to like companies where the CEO and other insiders are buying shares like crazy, which is the case with Opko. Buyout fever could easily send Life Technologies shares even higher in the coming weeks and months.

Little Sangamo might be the most humongous of the three over time. There's plenty of risk, of course, in a clinical-stage company. If Sangamo finds success with its gene modification approach, though, this one could be a game-changer.