FXYD3 and colorectal cancer: FXYD-3 is an 8-kDa trans-membrane protein and acts as a chloride channel or chloride channel regulator.20 FXYD-3 is overexpressed in several types of cancers including colorectal cancer.11,20,21 In our previous study, we found that FXYD-3 expression in the primary tumours was, or tended to be increased compared with normal mucosa regardless of RT.