The treatment strategy of bladder cancer has evolved not only through the traditional modalities of surgery and chemotherapy but also by immunotherapy over the past several decades. Immunotherapies such as intravesical Bacillus Calmette-Guérin (BCG) vaccines and immune checkpoint blockades (ICBs) are sometimes used for treating patients with bladder cancer, especially those who develop resistance to conventional first-line treatments such as surgery and chemotherapy.