Mitochondrial 3-hydroxyacyl-thioester dehydratase, which may be involved in fatty acid biosynthesis. a (3R)-hydroxyacyl-[ACP] = a (2E)-enoyl-[ACP] + H2O (3R)-hydroxyhexanoyl-[ACP] = (2E)-hexenoyl-[ACP] + H2O (3R)-hydroxydecanoyl-[ACP] = (2E)-decenoyl-[ACP] + H2O Highly expressed in heart and liver. Expressed at lower levels in skeletal muscle, spleen, kidney and placenta. This protein is produced by a bicistronic gene which also produces the RPP14 protein from an overlapping reading frame. Belongs to the HTD2 family.