PRKN and breast cancer: It was reported that up-regulation of Parkin expression can inhibit cancer cell growth in hepatocarcinoma, colon cancer, breast cancer and glioblastoma (Wang et al., 2004; Poulogiannis et al., 2010; Tay et al., 2010; Veeriah et al., 2010), while down-regulation of Parkin expression promotes cell proliferation and tumorigenesis in pancreatic cancer (Sun et al., 2013).