KLRK1 and neoplasm: Furthermore, additional blockade of NKG2D in NK- and CD4-depleted mice did not result in a statistically significant difference, although a trend toward increased tumor growth was observed in some mice (Figure 1B–E), raising the possibility that the antitumor effect of CD4+ T cell depletion may be at least partially mediated by NKG2D signaling in T cells rather than in NK cells.