Russian's Federal Security Service (FSB) asserts that the Gostaresh Scientific Research Center (GSRC) is the Defense Industries Organization's (DIO) primary missile engineering research facility. [1] The complex's precise location and purpose are unclear, but open source literature suggests it may house a large number of DIO entities, including the Sanam Industries Group or Department 140; the Mechanical System Industrial Group or Departments 142 and 158; the Education and Research Institute (ERI), formerly known as the Scientific Research Group, or Department 148/3; the University of Science and Defense Technologies or Department 149/d; and the Special Industrial Groups of the Ministry of Defense or Department 154. [2]

Sources:
[1] Mikhail Kirillin, "Several U.S. Firms Engaged in Developing Missile Equipment Have Links With Iranians," Yadernyy Kontrol Dossier in Yadernyy Kontrol (Moscow), March-April 1998, No.2 Vol. 38, pp. 37-43, PIR Center, Publications Archives, www.pircenter.org.
[2] Al Venter, Iran's Nuclear Option (Pennsylvania: Casemate, 2005), p.37.