SNORD115 and embryonal carcinoma: Previous in vitro and ex-vivo (i.e., transfection in non-neuronal cell culture or embryonic carcinoma cell line P19 neuronal differentiation) analyses suggested that Snord115 targets exon Vb of the 5-Ht2c receptor pre-mRNA and restricts access of the splicing machinery to an alternative 5′-donor splice site, which is located 13nt upstream from the snoRNA targeting region (Fig. 1A)29,30,38.