Clinical relevance of serum interleukin-6 in Crohnʼs disease: Single point measurements, therapy monitoring, and prediction of clinical relapse - Reinisch, W; Gasche, C; Tillinger, W; Wyatt, J; Lichtenberger, C; Willheim, M; Dejaco, C; Waldhor, T; Bakos, S; Vogelsang, H; Gangl, A; Lochs, H (Am J Gastroenterol, 1999)