Bladder cancer refers to any of several types of malignant growths of the urinary bladder. It is a disease in which abnormal cells multiply without control in the bladder. The most common type of bladder cancer begins in cells lining the inside of the bladder and is called transitional cell carcinoma. This book reviews research in the study of bladder cancer including recent advances in intravesical therapy for non-muscle invasive bladder cancer; molecular and genetic mechanisms in defining distinct genetic pathways of bladder cancer, and molecular proteins in urothelial carcinoma.