Comment
If url contains "=" (like cgi argument) then variable name has to be specified i.e.
{ GetFile(url=http://www.nature.com/cgi-taf/DynaPage.taf?file=/emboj/journal/v17/n19/full/7591266a.html&filetype=pdf, fname=Sox-Col2a1-regulation.pdf) }
File is downloaded in the attachment folder: