PIK3C3 and breast cancer: We reported that the protein levels of VPS34 were upregulated in highly tumorigenic breast cancer cell lines (MDA-MB-231, MDA-MB-468, and SKBR3) as compared with relatively low tumorigenic breast cancer cell lines (MCF-7 and T47D) and a normal cell line (MCF-10A), and that VPS34 lipid kinase activity is required for Src-induced cellular transformation [30].