Figure 5a: Alteration of mRNA expression of apoptosis related genes in MCF-7 cells post 24 and 48 h treatment with different concentrations of C.cerastes (0.75, 1.5 & 3 μg/ml) and V.lebetina (1.25, 2.5 & 5 μg/ml) venoms demonstrating up regulation of p53 and Bax genes and down regulation of BCl-2 expression levels compared to negative cell control. M: Marker; C: control untreated cells.