IL6 and neoplasm: When C57BL/6 mice bearing a syngeneic tumor were used (Fig. 4b, EXP.2), we detected an increase in both TNF-α (Fig. 5c) and IL-6 (Fig. 5d) in hAd-GFP IV injected mice just as we did using C57BL/6 mice without tumor; however, the increase in IL-6 using hAd-GFP IV injected mice was less substantial than that of the C57BL/6 mice without tumor.