Cartilage

Cartilage is a specialized connective tissue composed primarily of chondrocytes embedded within an abundant extracellular matrix rich in collagen fibers and proteoglycans such as aggrecan. It exists in three main types—hyaline cartilage, fibrocartilage, and elastic cartilage—which differ by their fiber content and anatomical location. Cartilage provides structural support to various body parts including joints (as articular cartilage), the rib cage, ear, nose, bronchial tubes, and intervertebral discs. Unlike bone or muscle tissue, it lacks blood vessels and nerves; nutrients diffuse through the matrix to reach chondrocytes[1][4][6]. Cartilage plays critical roles in shock absorption, enabling smooth joint movement with minimal friction. It has limited self-repair capacity due to its avascular nature. Diseases involving cartilage include osteoarthritis—a degenerative condition marked by breakdown of articular cartilage—and rare tumors such as chondrosarcoma[2][6]. Note: "Cartilage" refers to a tissue, not to any specific molecule/receptor/enzyme/transporter/targetable protein. Therefore it does not fit the definition of a therapeutic target at the molecular level. If you are seeking information on specific molecules within cartilage that serve as drug targets—such as collagen type II alpha 1 chain (COL2A1), aggrecan (ACAN), or enzymes involved in matrix degradation like MMPs—please specify which component you are interested in for structured data extraction[2][4].