BAX and hepatocellular carcinoma: Realgar quantum dots (RQDs) at 30 μg/mL declined Bcl-2 expression and elevated Bax expression in hepatocellular carcinoma HepG2 cells, promoted Cyt C release with complete loss of MMP and triggered an apoptotic enzyme cascade effect, together with the upregulated mRNA expression of Chop10 and GRP78, which suggested that RQDs induced apoptosis and necrosis probably via ERS, loss of MMP, and an elevated Bax/Bcl-2 ratio (Qin et al., 2015).