Among various gene expressions induced by both types of tumor promoter, we think that there is an essential gene commonly involved in signal transduction for tumor promotion in various organs: based on evidence that human fibroblasts treated with okadaic acid and TNF-α showed biochemical similarity, okadaic acid was thought to mimick the phorphorylation pattern induced by TNF-α or IL-1 (Guy et al. 1992). Here, TNF is linked to neoplasm.