Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Prostate Cancer ?
    ### Response:
    How Tumors Form The body is made up of many types of cells. Normally, cells grow, divide, and produce more cells as needed to keep the body healthy and functioning properly. Sometimes, however, the process goes wrong -- cells become abnormal and form more cells in an uncontrolled way.
    