Therapeutic variations on this theme include double stranded RNA (dsRNA) in the form of custom-designed siRNAs, mimics to the endogenously expressed dsRNA called microRNAs (miRNAs), or single stranded ASOs that are designed to inhibit miRNAs.39 A recent approval by the FDA includes patisiran, a siRNA with a lipid-based delivery system40 for the treatment of transthyretin-mediated amyloidosis,41 with similar systems now also in use in SARS-CoV-2 mRNA vaccines. The gene discussed is TTR; the disease is amyloidosis.