interleukin

inter- +‎ leuko- +‎ -in;

• inter-: from Latin inter- (“between, amid”), a form of prepositional inter (“between”).
• leuko: from Ancient Greek λευκός (leukós, “white”)
• -in: from French -ine, from Latin -īna, feminine of -īnus "of" or "belonging to"

interleukin (plural interleukins)

1. (biochemistry) Any of a group of cytokine proteins important in the regulation of lymphocyte function.