Acts as a negative regulator of mTOR activity. Interacts with FBXW5; TNFAIP8L1 competes with TSC2 to bind FBXW5 increasing TSC2 stability by preventing its ubiquitination. Detected in wide variety tissues, such as neurons in brain, hepatocytes, germ cells of female and male reproductive organs, muscular tissues and variety types of cells of the epithelial origin (at protein level). Up-regulated by oxidative stress and by 6-hydroxydopamine (6-OHDA) in dopaminergic neurons. Belongs to the TNFAIP8 family.