Progesteron-induced blocking factor (PIBF): A potential novel tumour marker for screening and follow-up patients for gastrointestinal cancer - Polgár, B ; Diófalvi, K ; Schäfer, E ; Oreskovich, K ; Gyökeres, T ; Hamvas, J ; Varga, G ; Pap, Á ; Schwab, R ; Szekeres-Bartho, J (Zeitschrift für Gastroenterologie, 2004)