Promotes attachment of chondrocytes, fibroblasts, and osteoblasts. This binding is mediated (at least for chondrocytes and fibroblasts) by the integrin alpha(2)beta(1). May play an important role in the regulation of chondrocyte growth and proliferation (By similarity). Mostly monomeric. Present in femoral head and rib cartilage, as well as in tendon. Detected in bone marrow. Belongs to the small leucine-rich proteoglycan (SLRP) family. SLRP class IV subfamily.