Then the primary transcripts (pri-miRNAs) from intergenic regions undergo nuclear processing into a stem-loop precursor of approximately 70 nt (pre-miRNA) by the Drosha-DGCR8 (DiGeorge syndrome chromosome region 8) complex, a nuclear RNase III complex, while the intronic transcripts bypass Drosha processing [3]. This evidence concerns the gene DROSHA and 22q11.2 deletion syndrome.