TNF and cancer: Suminami et al. previously demonstrated that overexpression of SCCA1 in several kinds of tumor cells protected against apoptosis induced by an anti-cancer drug (7-ethyl-10-hydroxycamptothecin), by TNF-α, and by IL-2–activated natural killer (NK) cells, whereas silencing SCCA1 increased sensitivity to apoptosis induced by an anti-cancer drug (etoposide) and by TNF-α [4].