For MS drugs, natalizumab (n = 231) and fingolimod (n = 51, 58 for all drugs targeting S1P modulators) had the highest number of PML cases but ocrelizumab (n = 28) and other CD20-targeting drugs also have an appreciable number of reported PML cases (44 total in the MS section for all CD20 drugs). Here, MBTPS1 is linked to progressive multifocal leukoencephalopathy.