GPX3 and Hemoglobin C Measurement: Fisher's Exact test showed that normal bladder tissues have higher expression level of GPX3 (P = 0.016) and ECM1 (P = 0.001) than HGBC tissues, while no differences were found for expression levels of CRYAB, CGNL1 and CRNN (P > 0.05) (Table 5).