Still on Hemophilia-related pathologies a very interesting study was conducted by Balestra et al. [54] that challenged the efficacy of a U1 snRNA-mediated strategy for splicing mutations occurring at the 3′ss, 5′ss or within exon 5 of the F8 (FVIII) gene (see Table 1) and associated with different severity degrees of Coagulation factor VIII (FVIII) deficiency (Hemophilia A). This evidence concerns the gene F8 and hyperinsulinemic hypoglycemia, familial, 4.