Surprises in HIV Structure (IMAGE) European Molecular Biology Laboratory Caption Surprisingly, the building blocks in immature HIV (centre) are arranged differently from those of immature Mason-Pfizer Monkey Virus (left). To form the mature virus, HIV's building blocks take on yet another arrangement (right). Credit EMBL/F.Schur Usage Restrictions EMBL press and picture releases including photographs, graphics and videos are copyrighted by EMBL. They may be freely reprinted and distributed for non-commercial use via print, broadcast and electronic media, provided that proper attribution to authors, photographers and designers is made. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.