Order and judgment unanimously affirmed without costs. Memorandum: Supreme Court properly granted defendant's cross motion to dismiss plaintiff's cause of action for breach of the promise of confidentiality. A waiver may be express or implied, and "may be established * * * by acts and conduct manifesting an intent and purpose not to claim the alleged advantage or from which an intention to waive may reasonably be inferred" (57 N.Y. Jur 2d, Estoppel, Ratification and Waiver, § 81, at 117). By authorizing her friend to inquire about her condition and concerns, plaintiff waived her right to enforce defendant's duty to maintain confidentiality. Further, by authorizing her friend to use her influence with hospital officials to see whether she was getting the best care possible, plaintiff waived the physician-patient privilege (see, CPLR 4504).