A mutated Hsap\CC2D1B coding sequence, in which DM14 repeats 1 and 2 have been deleted and a R412E amino acid replacement has been introduced into DM14 repeat 3, is expressed under the control of l(2)gd1 regulatory sequences (548bp from upstream of the translational start site and 553bp from downstream of the translational stop site are present). The coding sequence is tagged at the C-terminal end with Tag:HA.