It is only one of nine accounting firms in the U.S. that the Sarbanes-Oxley Act requires to be inspected annually by the PCAOB(Public CompanyAccountingOversightBoard) because the firm audits over 100 companies that are traded on stock exchanges here in the United States (18 of them Chinese).
The PublicCompanyAccountingOversightBoard(PCAOB), an independent agency of the Securities and Exchange Commission (SEC) created by SOx, develops those auditing standards and regulates external auditors of public companies.