This phenomenon was first demonstrated at the α-globin locus in a case of α-thalassemia where the LUC7L gene is juxtaposed upstream of HBA2. Here, LUC7L transcription extends through the HBA2 promoter CGI which is subsequently DNA methylated and silenced (Tufarelli et al., 2003). This evidence concerns the gene LUC7L and thalassemia.