IL6 and neoplasm: Given the fact that the in vivo tumour milieu contains copious amounts of IL-6 after PDT and macrophages are a component of the PDT-induced host cell infiltrate (Gollnick et al, 1997; Henderson et al, 2004), these findings argue for a possible role of sIL-6Rα and IL-6/sIL-6Rα complex in PDT-treated tumours.