(E-G) Luciferase-expressing MIA PaCa-2 cells (2×106) infected with lentivirus were injected via tail vein into NSG mice (n = 6/group). At 12 weeks after injection, mice were subjected to bioluminescent imaging, and images were recorded (E) and bioluminescent signals were quantified (F). Bioluminescent flux (photons s-1 sr-1 cm-2) was determined for lesions in lung, the ends of the box are the upper and lower quartiles and the box spans the interquartile range; the median is marked by a vertical line inside the box; the whiskers are the two lines outside the box that extend to the highest and lowest observations. Lungs were isolated from mice, stained with Bouin's solution, and photographed (G). The white spots on lungs (stained in yellow) are metastatic tumors. * P < 0.05; NS, no significance. 