Anti-fucose kinase antibodies are used for the immunodetection of the protein encoded by the FCSK gene. In humans, the canonical protein has a reported length of 1084 amino acid residues and a mass of 117.6 kDa. Alternative splicing is reported to yield 2 different isoforms for this protein. It is reported to be expressed in fibroblasts. It is a member of the GHMP kinase protein family. The gene encoding this protein is implicated in Congenital disorder of glycosylation with defective fucosylation. Other names for this target antigen include L-fucose kinase and fucokinase. Gene orthologs have been identified in the mouse, rat, bovine, frog, zebrafish, chimpanzee and chicken species.