BCL2 and cancer: As seen in Fig. 7, exposure of hepatic Hep-G2 cancer cells to Y2O3 NPs at the IC50 concentration (13.15 μg/ml) resulted in a statistically significant (p < 0.001) increase in the expression level of apoptotic p53 and mitochondrial ND3 genes, along with marked decrease (p < 0.001) in the expression level of the anti-apoptotic Bcl2 gene compared to their expression level in untreated Hep-G2 cells.