Any antigen that stimulates autoantibodies in the organism that produced it; an antigen produced by the self (that is, by one's own tissues).

The decade from 1820 to 1829.

(transitive, intransitive, UK) To alternate with each other, often in the same post or location. / (transitive, intransitive, UK) To alternate between two people.

(organic chemistry) An organic compound related to choline, with the difference that the terminal carboxylic acid group of trimethylglycine has been reduced to a hydroxyl group in choline.