Sirena's practice focuses on representing banks and other corporate entities during criminal investigations and complex civil litigation. She has represented a wide variety of clients in state and federal courts, including clients in the healthcare, banking and insurance industries. She has experience defending False Claims Act actions, nationwide consumer class actions, complex contract disputes and unfair competition actions. Sirena also has experience advising and defending entities in a variety of white collar criminal matters, regulatory enforcement matters and internal investigations. Her white collar defense practice includes the representation of banks and corporations at all phases of government investigations, including responding to grand jury subpoenas and civil investigative demands. Sirena conducts internal investigations, both internationally and domestically, for banks and corporate entities in response to allegations of misconduct or to government inquiries.