The suffix -kin is used in naming interleukin-type substances except for interleukin 3 (IL-3), which was classified as a pleiotropic colony-stimulating factor and assigned the "plestim" stem (e.g., daniplestim).
The "kin" nomenclature series was divided into subgroups with an adjuvant stem representing the numerical class of the interleukin followed by the kin suffix.
The subgroups are:
-nakin
interleukin 1 derivatives
-onakin
interleukin 1 a derivatives
-benakin
interleukin 1 b derivatives
-leukin
interleukin 2 derivatives
-trakin
interleukin 4 derivatives
-penkin
interleukin 5 derivatives
-exakin
interleukin 6 derivatives
-eptakin
interleukin 7 derivatives
-octakin
interleukin 8 derivatives
-nonakin
interleukin 9 derivatives
-decakin
interleukin 10 derivatives
-elvekin
interleukin 11 derivatives
-dodekin
interleukin 12 derivatives
