I agree, use the web. A quick search on Yahoo! using the keyword "vimentin" reveals this as the first hit:
"Vimentin is of limited value as a diagnostic tool; however, when used in combination with other antibodies (in panels) it is useful for the subclassification of a given tumor. Expression of vimentin, when used in conjunction with keratin, is
helpful when distinguishing melanomas from undifferentiated carcinomas and large cell lymphomas."
(from
http://www.cellmarque.com/2000/Pages/catalog/vim.html)