Fig. 2 showed that CD8 deficiency almost completely blocked the tumor growth retardation of sulindac (Fig. 2B), further validating the inferred function of adaptive immunity on tumor reduction. The anti-tumor effect was not abrogated by depletion of CD4+ T cells. There was also observable tumor inhibition behavior of sulindac by treating with isotype immunoglobin simultaneously (Fig. 2B). Here, CD4 is linked to neoplasm.