Yes, Sanofi-Aventis US is "just" a subsidiary, but it's still one of the largest pharmaceutical companies in the country. As the US operations of global drugmaker Sanofi, the company develops, manufactures, and markets pharmaceutical products for a range of ailments. Its principal therapeutic areas include cardiovascular disease, central nervous system ailments, internal medicine, metabolic disorders, oncology, and ophthalmology. Some of its key products include injectable insulin Lantus, cancer drug Taxotere, thrombosis treatment Lovenox, and blood thinner Plavix. Also known as simply Sanofi US, the firm markets its parent's products in the US through its thousands of field sales professionals.