II is the Roman numeral for 2. . II may also refer to: Biology and medicine. Image intensifier, medical imaging equipment. Invariant chain, a polypeptide involved in the formation and transport of MHC class II protein. Optic nerve, the second cranial nerve. Economics. Income inequality, or the wealth gap, in economics. Internationalization Index, used by the UN to rank nations and companies in evaluating their degree of integration with the world economy. Institutional Investor (magazine), an American finance magazine. Music. Supertonic, in music. ii, a 2018 song by CHVRCHES. Albums.
https://en.wikipedia.org/wiki/II