We further performed anchorage-independent growth assays to investigate the effects of PLPP4 on the tumorigenic activity of lung carcinoma cells and found that silencing PLPP4 not only reduced the number of colonies formed by A549 and Calu-3 cells, but also significantly decreased the colony size of lung carcinoma cells (Fig. 4g). This evidence concerns the gene PLPP4 and lung carcinoma.