To render natural killer (NK) cells with tumor‐specificity, synthetic oligonucleotide aptamers are anchored on cell surfaces to produce aptamer‐engineered NK cells (ApEn‐NK). Under surface‐anchored aptamer guidance, ApEn‐NK selectively target tumor cells and thus, specifically kill the cells of interest with high efficacy. This study demonstrates a new approach for tumor‐specific immunotherapy. This is reported by Youli Zu and co-workers in the article linked here: https://doi.org/10.1002/smll.201900903. To learn more, please visit the Small homepage.