microRNA is a "non-coding RNA" molecule. This means that it does not translate into a protein. These are sometimes also called "non-messenger" RNA molecules.

An antimir is any agent which counteracts microRNA activity.

microRNA

Women are not necessarily healthier than men. Women on average do live 5-10 years longer than men because women have the XX chromosomes and men have the XY chromosomes. This matters because the X chromosome contains microRNA (small strands of ribonucleic acid). MicroRNA tells our genes what or what not to do. MicroRNA also plays a role in our body's immune system which can help ward off infections and cancer. A lot of this microRNA is contained in the X chromosome, basically doubling women's chances.

An antagomir is a member of a class of chemically engineered oligonucleotides used to silence endogenous microRNA.