Cancer cells, especially U-2 OS cells, carrying shNPM1 No. 1 showed a higher growth rate (i.e., stronger suppression of p27) than cancer cells carrying shNPM1 No. 2, although the former showed a lower expression of NPM1 than the latter (Figure 3B,D), suggesting that NPM1, depending on its expression level, may exert dual effects on p27 function (see Discussion). The gene discussed is NPM1; the disease is cancer.