interleukin

noun

in·​ter·​leu·​kin ˌin-tər-ˈlü-kən 

: any of various cytokines of low molecular weight that are produced by lymphocytes, macrophages, and monocytes and that function especially in regulation of the immune system and especially cell-mediated immunity

—often used with an identifying number

—abbreviation IL see also interleukin-1, interleukin-2, interleukin-6

Examples of interleukin in a Sentence

Recent Examples on the Web

Vitamin B6 is vital in producing T-lymphocytes and interleukins, essential players in an optimally functioning immune system. — Chelsea Rae Bourgeois, Health, 20 Dec. 2025

In addition, the elevated interleukin 1B is typically seen in people with illnesses and inflammation, but this group was pretty healthy. — New Atlas, 12 Apr. 2025

Meanwhile, their interleukin 1B levels–those linked to inflammation–were higher. — Andrew Paul, Popular Science, 10 Apr. 2025

These include nitric oxide, tumor necrosis factor, and interleukin 6. — Heidi Moawad, Verywell Health, 23 Sep. 2024

For example, the concentration of a cytokine called interleukin 6 (IL-6) can increase up to a thousandfold during an infection. — IEEE Spectrum, 22 Oct. 2014

Word History

Etymology

inter- + leuk- + -in entry 1

First Known Use

1979, in the meaning defined above

Rhymes for interleukin

• glucan
• lukan

Medical Definition

interleukin

noun

in·​ter·​leu·​kin ˌin-tər-ˈlü-kən 

: any of various compounds of low molecular weight that are produced by lymphocytes, macrophages, and monocytes and that function especially in regulation of the immune system and especially cell-mediated immunity