TST and hydrops fetalis: It would be tempting to hypothesize that small structured RNA molecules, such as HD and HF, might be recognized by the machinery of the miRNA import and targeted to mitochondria by AGO2 and/or another components of the RNA-inducible silencing complex (RISC), which could thus perform the “second job” as mitochondrial targeting factors, similarly to the enzymes enolase or rhodanese.