United Therapeutics Reports Fourth Quarter and Annual 2007 Financi...(he table below summarizes the components...)

Three Months Ended Years Ending

December 31, December 31,

2007 2006 2007 2006

Revenues:

Net product sales $56,899 $44,147 $201,348 $153,448

Service sales 2,172 1,679 7,435 6,184

Distributor fees 827 - 2,160 -

Total revenues $59,898 $45,826 $210,943 $159,632

The increases in revenues resulted primarily from growth in sales of Remodulin.

Operating Expenses. Our operating expenses include research and development expenses, sales and marketing expenses, costs of product sales and cost of service sales.

Research and development expenses consist primarily of salaries and related expenses, costs to acquire pharmaceutical products and product rights for development, and amounts paid to contract research organizations, hospitals and laboratories for the provision of services and materials for drug development and clinical trials. The table below summarizes research and development expenses by major project and non-project components for the three months and year ended December 31, 2007 and 2006 (dollars in thousands):

Three Months Ended Years Ending

December 31, December 31,

2007 2006 2007 2006

Project and non-project:

Cardiovascular $8,570 $11,276 $38,459 $33,005

Cancer 3,189 3,231 13,874 10,462

Infectious disease 278
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