Figure 1: Schematic diagram of piggyBac constructs used to establish stable cell lines. (a) pIR-HER2-puromycin. This construct contains HER2 gene in addition to puromycin gene. It was used in cotransfections for making stable cell lines expressing HER2. (b) pIR-GFP-Luc. This construct contains the fusion gene of GFP and luciferase. It was used in all the co-transfections in which the GFP-Luc fusion gene serves as a convenient marker for identifying the stably transfected cells. The locations of the promoter, the polyA signal, and the inverted terminal repeats (ITR) are indicated.