HPGD and pulmonary fibrosis: Small molecule 15-PGDH inhibitors represent a promising therapeutic strategy in elevating PGE2 levels to promote tissue stem cell proliferation and to accelerate tissue regeneration and repair, as demonstrated by efficacy in multiple mouse models of human diseases that include colitis, pulmonary fibrosis, aplastic anemia, sarcopenia, and hematopoietic recovery after bone marrow transplant4–6,14–16.