The Dallas-Fort Worth Metroplex has one of the largest concentrations of corporate headquarters for publicly traded companies in the United States. The city of Dallas has 12 Fortune 500 companies and the DFW region as a whole has 20. Comerica Bank and AT&T located their headquarters in Dallas. Irving is home to four Fortune 500 companies of its own, including ExxonMobil, the most profitable company in the world and the second largest by revenue, Kimberly-Clark, Fluor (engineering), and Commercial Metals. Additional companies headquartered in the Metroplex include Southwest Airlines, American Airlines, RadioShack, Neiman Marcus, 7-Eleven, Brinker International, AMS Pictures, id Software, ENSCO Offshore Drilling, Mary Kay Cosmetics, Chuck E. Cheese’s, Zales and Fossil. Corporate headquarters in the northern suburb of Plano include HP Enterprise Services, Frito Lay, Dr Pepper Snapple Group, and JCPenney. Many of these companies – and others throughout the DFW metroplex – comprise the Dallas Regional Chamber.