Endometriosis-specific secretory protein

A method and kit of diagnosing endometriosis in a female patient suspected of having endometriosis. The method includes obtaining a sample from the patient. The sample is analyzed to detect the presence of a purified and isolated endometriotic haptoglobin designated ENDO-I and functional analogs thereof. A therapeutic for treating endometriosis by modulating the expression of a purified and isolated endometriotic haptoglobin designated ENDO-I and functional analogs thereof and a pharmaceutically acceptable carrier.