By administering an effective amount of a RANKL binding molecule that acts on cartilage progenitor cells and / or mesenchymal stem cells, promotes cartilage differentiation, proliferation and maturation of those cells, enhances chondrocyte differentiation, and causes chondrocyte proliferation A method for inducing proliferation / differentiation of chondrocytes or increasing cartilage matrix production and a pharmaceutical composition for inducing proliferation / differentiation of chondrocytes or increasing cartilage matrix production. Acting on cartilage progenitor cells and / or mesenchymal stem cells, (a) promoting differentiation of cartilage progenitor cells and / or mesenchymal stem cells, (b) promoting proliferation of cartilage progenitor cells and / or mesenchymal stem cells, (C) a compound that causes at least one of promotion of maturation of cartilage progenitor cells and / or mesenchymal stem cells, (d) enhancement of chondrocyte differentiation, (e) chondrocyte proliferation, and (f) increased cartilage matrix production A pharmaceutical composition for treating or preventing cartilage-related diseases, comprising as an active ingredient.軟骨前駆細胞及び／又は間葉系幹細胞に作用しそれらの細胞の軟骨分化、増殖、成熟を促進し、軟骨細胞分化を増強し、軟骨細胞の増殖を引き起こすＲＡＮＫＬ結合分子を有効量投与することにより軟骨細胞の増殖・分化を誘導し、あるいは軟骨基質産生を増加させる方法及び軟骨細胞の増殖・分化を誘導し、あるいは軟骨基質産生を増加させるための医薬品組成物の提供。軟骨前駆細胞及び／又は間葉系幹細胞に作用し、（ａ）軟骨前駆細胞及び／又は間葉系幹細胞の分化の促進、（ｂ）軟骨前駆細胞及び／又は間葉系幹細胞の増殖の促進、（ｃ）軟骨前駆細胞及び／又は間葉系幹細胞の成熟の促進、（ｄ）軟骨細胞分化の増強、（ｅ）軟骨細胞の増殖、並びに（ｆ）軟骨基質産生増加の少なくとも１つを引き起こす化合物を有効成分として含む、軟骨謝疾患の治療又は予防のための医薬組成物。
