Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) bladder cancer ?
    ### Response:
    Bladder cancer is a disease in which certain cells in the bladder become abnormal and multiply without control or order. The bladder is a hollow, muscular organ in the lower abdomen that stores urine until it is ready to be excreted from the body. The most common type of bladder cancer begins in cells lining the inside of the bladder and is called transitional cell carcinoma (TCC).
    