Directed evolution, a laboratory simulation of Darwinian natural selection, employs random mutagenesis and recombination coupled with human-designed selection pressures to sift through proteins for those exhibiting desired characteristics, thereby facilitating the artificial evolution of molecules and cells.

Drawing inspiration from the traditional Chinese 'Sword Tomb', this study introduces a novel evolutionary strategy to refine the Natural Killer (NK) cell receptor repertoire, akin to selecting the most fitting sword for each battle against tumor, to counteract the diverse and elusive nature of tumor cells.