Tollip, also known as Toll interacting protein, is a 30 kDa ubiquitin-binding protein that is a component of the signaling pathway of IL-1 and Toll-like receptors. It performs multiple functions and is classified as an adaptor protein. Tollip interacts with IRAK-1 (IL-1 receptor-associated kinase 1) prior to IL-1? stimulation and suppresses the kinase activity of IRAK-1. Tollip also associates with Tom1 forming a complex which regulates endosomal trafficking of ubiquitinated proteins.