“…HuD, HuC, and Hel-N1 show 82 ± 90% sequence homology (King et al, 1994;Sakai et al, 1993;Szabo et al, 1991). In addition, they show an *54% homology to the Drosophila melanogaster RNA-binding proteins Sex-lethal and ELAV (King et al, 1994;Szabo et al, 1991), which participate in alternative splicing (Baker, 1989;Koushika et al, 1996). A role for the Hu proteins in neuronal di erentiation and survival is implied by their expression pattern in avian neural crest cells (Marusich and Weston, 1992;Marusich et al, 1994;Wakamatsu and Weston, 1997) and mouse embryos (Okano and Darnell, 1997), as well as in neurons of adult human central and peripheral nervous systems .…”