Procholecystokinin as Marker of Human Ewing Sarcomas Posted on August 28, 2004 by Barry Sugarman Reply Please see the following link: http://clincancerres.aacrjournals.org/cgi/content/abstract/10/16/5523?etoc or http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15328192