CASP3 and hepatocellular carcinoma: Apoptosis has been clearly established as one of the mechanisms of quercetin-induced cell death in HCC [22,24,27,30,31,32,33,50,51,52,53], as it was demonstrated by the increase in proapoptotic proteins expression, such as Bax and cleaved caspases-3 and -9 [22,24,27,31,32,33,50,51,52,53], and the opposite trend in the levels of antiapoptotic proteins, for instance Bcl-2 and Mcl-1 [24,27,32,33,50,51,52].