As shown in Figure 4C and 4D, on the 16th day, the mean of tumor weight was significantly decreased in the group of mice injected with A549-shRNA-STIM1 cells (0.23±0.08 g) as compared to the group of those injected with A549-shRNA-control cells (0.96±0.27 g) (P<0.05), suggesting that silencing STIM1 markedly suppressed the growth and formation of tumors of A549 cells in in vivo experiments. Here, STIM1 is linked to neoplasm.