To elucidate the cellular localization of Phosphoglycerate mutase (PGAM1) type B in the brain and periphery, immunocytochemical studies were performed. The purified antigen used to generate the antiserum to PGAM1 was run on an SDS-PAGE gel, stained with coomassie blue, which yielded one sharp band at 29 kDa. Immunocytochemistry of formalin perfused rats revealed distinct localization of PGAM1 in the endothelium of the capillaries and arteries of the brain, liver and kidneys. Since enhanced glycogenesis is a well-known characteristic of cancer cells, it is of interest that sustained angiogenesis is a hallmark that distinguishes cancer cells from their normal counterparts. In view of the fact that PGAM1 increases in a variety of tumors, we suggest that PGAM1 may have a pathological role of vascular invasion into cancerous tissue.