The nuclear matrix protein CIZ1 facilitates localisation of Xist RNA to the inactive X-chromosome territory by Ridings-Figueroa, R, Stewart, E, Nesterova, T, Coker, H, Pintacuda, G, Godwin, J, Wilson, R, Haslam, A, Lilley, F, Ruigrok, R, Bageghni, S, Albadrani, G, Mansfield, W, Roulson, J, Brockdorff, N, Ainscough, J, Coverley, D