A13 or A-13 may refer to:
== Biology == ATC code A13 Tonics, a subgroup of the Anatomical Therapeutic Chemical Classification System British NVC community A13 (Potamogeton perfoliatus - Myriophyllum alterniflorum community) Subfamily A13, a rhodopsin-like receptors subfamily
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).