NME1 promotes colonization of melanoma sphere-derived stem cells in lung tissue (experimental metastasis). 451Lu cells expressing eGFP were treated with lentiviruses expressing either shRNA-scr, shNME1a, or shNME1b as indicated, and used to generate melanoma spheres. After 4d of melanoma sphere growth, cultures were dissociated into single cells and injected into the tail veins of NSG mice (105 cells/mouse). Lungs were imaged for eGFP fluorescence at 5.5 weeks post-injection. A, eGFP-expressing lung colonies from 451Lu cells expressing shRNA-scr or shNME1a. Outlines of left and right lungs are denoted with dotted lines. B, Lung colony formation from 451Lu cells expressing shRNA-scr or shNME1b. C, Quantification of colony formation in lungs shown in panel A. *p ≤ 0.02. D, Quantification of colony formation in lungs shown in panel B.