GGPS1 and lung adenocarcinoma: However, transwell assay revealed that the down‐regulation of GGPPS significantly inhibited the migration and invasion of lung adenocarcinoma cells (SPCA‐1, PC9 and A549 cells), and up‐regulation of GGPPS significantly increased the migration and invasion of A549 cells (P < 0.01, Figs 5 and S3D).