NCR1 and neoplasm: Interestingly, mice that received E4BP4 knockdown Smad3−/− NK cells (siE4BP4) exhibited a higher tumour growth rate, which was associated with lower levels of infiltrating NK1.1+CD3− NK cells and the expression of NKp46 when compared with those that received siT-bet Smad3−/− NK cells (Fig. 5c,d).