CASP3 and cancer: In addition, combinatorial treatment with RES has been reported to increase caspase-3 cleavage in several resistant cancer cells, including PC9/G cells [37]; MCF-7/TR cells [56]; MCF-7/DOX, a DOX-resistant subline of MCF-7 cells [58]; and SGC7901/DOX, a DOX-resistant subline of SGC7901 gastric cancer cells [26].