Integrin-linked kinase is an enzyme that in humans is encoded by the ILK gene involved with integrin-mediated signal transduction. Mutations in ILK are associated with cardiomyopathies. It is a 59kDa protein originally identified in a yeast-two hybrid screen with integrin β1 as the bait protein. Since its discovery, ILK has been associated with multiple cellular functions including cell migration, proliferation, and adhesion.

Integrin-linked kinases (ILKs) are a subfamily of Raf-like kinases (RAF). The structure of ILK consists of three features: 5 ankyrin repeats in the N-terminus, Phosphoinositide binding motif and extreme N-terminus of kinase catalytic domain. Integrins lack enzymatic activity and depend on adapters to signal proteins. ILK is linked to beta-1 and beta-3 integrin cytoplasmic domains and is one of the best described integrins. Although first described as a serine/threonine kinase by Hannigan, important motifs of ILK kinases are still uncharacterized. ILK is thought to have a role in development regulation and tissue homeostasis, however it was found that in flies, worms and mice ILK activity isn’t required to regulate these processes.

Animal ILKs have been linked to the pinch- parvin complex which control muscle development. Mice lacking ILK were embryonic lethal due to lack of organized muscle cell development. In mammals ILK lacks catalytic activity but supports scaffolding protein functions for focal adhesions. In plants, ILKs signal complexes to focal adhesion sites. ILKs of plants contain multiple ILK genes. Unlike animals that contain few ILK genes ILKs have been found to possess oncogenic properties. ILKs control the activity of serine/threonine phosphatases.