/in"teuhr looh'kin/ , Immunol.
any of several proteins released from certain cells, esp. macrophages, and having various effects on the activity of other cells, as promoting inflammation or enhancing T-cell proliferation. Abbr.: IL-1
[ 1979; INTER- + LEUK(OCYTE) + -IN 2 ; so called because such proteins act as agents of communication between different populations of leukocytes ]