Apart from a few zinc-finger proteins, such as WT1, BCL11A, Evi9, EWS, TLS, GLI, and CTCF, the function of the majority of zinc-finger proteins in tumour occurrence and development is unknown (Lee and Haber, 2001; Klenova et al, 2002; Liu et al, 2003; Dunaeva et al, 2003; Shing et al, 2003; Zwerner et al, 2003). The gene discussed is FUS; the disease is neoplasm.