Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Wilms Tumor ?
    ### Response:
    Wilms tumor is a rare type of kidney cancer. It causes a tumor on one or both kidneys. It usually affects children, but can happen in adults. Having certain genetic conditions or birth defects can increase the risk of getting it. Children that are at risk should be screened for Wilms tumor every three months until they turn eight.
    