NPM1 and cancer: Specifically, by directly binding with NPM1, the lncRNA is concentrated in the nucleolus and plays a critical role for the formation of NPM1 oligomers, which are main building blocks of the GC of the nucleolus and required for the functional activities of NPM1.20,22,33–37 Indeed, repression of the lncRNA RP11-196G18.22 generated phenotypes identical to those observed with NPM1 knockdown, i.e., disordered morphology and functions of the nucleolus and strong inhibition of proliferation of human cancer cells and neuronal progenitor cells (NPCs).