Since IL-6 acts differently from TNF-α, and can be replaced by other cytokines, we think that TNF-α is the first endogenous instigator for the sequence of cytokine cascade from IL-1 to IL-6 and subsequently returns to TNF-α in tumor promotion (Fig. 5) (Suganuma et al. 2002; Fujiki and Suganuma 2005). Here, IL6 is linked to neoplasm.