LUM and osteoarthritis: For example, biglycan and decorin, the two best-studied class I SLRP members, have been proven to interact with Toll-like receptors (TLR) 2 and 4, leading to the initiation of the inflammatory response.33,34 Similarly, Lumican displayed an upregulation in osteoarthritis and participated in the TLR-4-initiated proinflammatory events.35 OMD is a keratan sulfate SLRP expressed in bone and teeth.