Shares of biotechnology companies closed mixed Friday as the broader market tumbled over wider-than-expected losses at insurer American International Group Inc. and a spike in oil prices.
Here's how several key biotechnology stocks performed Friday:
Gilead Sciences Inc., down 47 cents to $53.64.
Amgen Inc., up 3 cents to $42.05.
Biogen Idec Inc., down 63 cents to at $62.07.
Genentech Inc., up 21 cents to $68.53.