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Merck makes pharmaceutical products to treat several conditions in a number of therapeutic areas, including cardiometabolic disease, cancer, and infections. Within cancer, the firm's immuno-oncology platform is growing as a major contributor to overall sales. The company also has a substantial vaccine business, with treatments to prevent pediatric diseases as well as human papillomavirus, or HPV. Additionally, Merck sells animal health-related drugs. From a geographical perspective, just under half of the company's sales are generated in the United States.

Bristol-Myers Squibb discovers, develops, and markets drugs for various therapeutic areas, such as cardiovascular, cancer, and immune disorders. A key focus for Bristol is immuno-oncology, where the firm is a leader in drug development. Bristol derives close to 70% of total sales from the U.S., showing a higher dependence on the U.S. market than most of its peer group.

Laboratory Corp. of America is one of the nation's two largest independent clinical laboratories, with roughly 20% of the independent lab market. The company operates approximately 2,000 patient-service centers, offering a broad range of 5,000 clinical lab tests, ranging from routine blood and urine screens to complex oncology and genomic testing.

Intuitive Surgical designs, manufactures, and markets da Vinci robotic surgical systems, and related instruments and accessories in the U.S. and internationally. The da Vinci system enables surgeons to perform a wide range of surgical procedures with shorter recovery periods and higher patient comfort. ISRG was founded in 1995 and is headquartered in Sunnyvale, California.