TFRC and bladder transitional cell carcinoma: The close association of TFR1 protein level with cell proliferation can also explain why it is overexpressed in many different types of tumors including adenocarcinoma [10], bladder transitional cell carcinoma [11], breast cancer [12], leukemia and lymphoma [13–15], pancreatic cancer [16], thyroid carcinoma [17], and tumor of the nervous system [18].