Quest Diagnostics is the nation's leading provider of diagnostic testing, information and services. Its clients include patients and consumers, physicians, hospitals, health insurers, employers and government agencies, touching 130 million patients annually. Quest Diagnostics offers patients and physicians the broadest access to diagnostic laboratory services through its nation-wide network of laboratories and patient service centers. Quest provides interpretive consultation through the largest medical and scientific staff in the industry, with approximately 400 M.D.'s and Ph.D.'s around the country. Quest is the leading provider of esoteric testing, including gene-based testing, and testing for drugs of abuse. Quest is also a leading provider of anatomic pathology services and testing for clinical trials. During 2004, Quest generated net revenues of $5.1 billion and processed over 137 million requisitions for testing. Each requisition form accompanies a patient specimen, indicating the tests to be performed and the party to be billed for the tests. Its customers include patients, physicians, hospitals, healthcare insurers, employers, governmental institutions and other commercial clinical laboratories. Quest operates a nationwide network of greater than 2,000 patient service centers, principal laboratories located in more than 30 major metropolitan areas throughout the United States, and approximately 155 smaller "rapid response" laboratories (including, in each case, facilities operated at our joint ventures). Quest provides full esoteric testing services, including gene-based testing, on both coasts through its Quest Diagnostics Nichols Institute facilities, located in San Juan Capistrano, California and Chantilly, Virginia. Quest also has laboratory facilities in Mexico City, Mexico, San Juan, Puerto Rico and Heston, England.