On the other hand, remarkable elevations in the expression level of apoptotic p53 and Bax genes along with significant decreases in the expression level of anti-apoptotic Bcl2 gene were seen after 48 h of lung cancer A-549 cells treatment with CaTiO3NPs (1670.65 μg/ml) compared to their expression level in the untreated A-549 cells (Table 3). This evidence concerns the gene BCL2 and lung cancer.