Growth inhibitory effects of combined treatment with levamisole and 5-FU on human colorectal adenocarcinoma grafted in nude mice : Van Ginckel R., Distelmans W.∗, De Brabander M., Callens M., Janssens B., Jagers E. and De Coster R., Janssen Research Foundation, B-2340 Beerse, Belgium; ∗Free University Brussels, Academic Hospital, B-1090 Jette, Belgium