Down-regulating STAT3 results in delayed HEL engraftment. Panel 1A, Optical CCD images of HEL (non-silenced control in the upper panel and shRNAmir in the lower panel) xenografts in NOD/SCID mice from day 28 and day 45. Panel 1B, Graphs showing correlation of luciferase gene expression in HEL xenografts (p=0.0079, Man-Whitney test). The graphs were generated from repeated scanning of the mice on days 14, 28, 35, 45, 53 and 72. Individual mean values (photons/s/cm²/sr) calculated from the regions of interest were plotted.