IL1B and neoplasm: The fact that endothelial cells undergoing apoptosis release interleukin -1 β (IL-1β) that via a paracrine loop in turn stimulates the expression of adhesion molecules on the endothelial cells (Hebert et al, 1998a; Chandra et al, 2003b) suggests that the following sequence of events for the recurrence of tumour cells at distant sites occur.