Topic: Progressive Multifocal Leukoencephalopathy (PML) Author: Heba Allah Zuhair Huaishan Editor: Abdel Rahman Bani Yassin, Ihda Bani Khalaf Reviewer: Ethar Hazaimeh Key words: JCV, PML, Progressive, multifocal, leukoencephalopathy, double-stranded DNA   Introduction Progressive multifocal leukoencephalopathy (PML) is a rare and frequently deadly viral infection marked by...