The StackExchange search seems to think this is a subjective question. I'm not sure about that. It seems pretty straightforward.
Agile methodologies of software development involve more than just the testing part of things. Developers, technical writers, and customer representatives (product owners) play a large part in the Agile world.
When it comes to regulated industries such as medical, financial, insurance, etc., however, there is a lot of formalized structure that needs to be satisfied. Formally documented specifications, design documents, test plans, test cases, risk assessments, etc., are all necessary in order to satisfy the different auditing agencies that all bases are covered and compliant with regulations.
Testing and Quality Assurance, however, are most heavily under the gun in these kinds of situations because we are the ones that are the "last line of defense" when it comes to making sure things are working well. When it comes to Agile development methodology as applies to testing, how do you satisfy all that required paper trail and other standard procedures and policies?