Pulmonary fibrosis treatment agent, ptprr expression-promoting agent, and kit for pulmonary fibrosis treatment

The purpose of the present invention is to provide a novel treatment agent for pulmonary fibrosis for which there is currently no effective drug therapy established. The present invention is a pulmonary fibrosis treatment agent containing mesenchymal stem cells. The pulmonary fibrosis is preferably usual interstitial pneumonia (UIP) or idiopathic pulmonary fibrosis (IPF). Also, the mesenchymal stem cells are preferably derived from adipose tissue or are allogeneic.