The present invention relates generally to the field of cancer diagnosis and treatment, and more particularly to compositions and methods that may be useful for eliminating cancer cells with stem-like characteristics. The disclosed compositions and methods may also be useful for managing breast cancer, ovarian cancer, cervical cancer or endometrial (uterine) cancer with metastases and visualizing the cancer cells in patient"s body. The compositions of the instant invention include human prolactin receptor antagonist G129R.