PTP4A3 and breast cancer: Thus, we used MCF-7 breast cancer cells, the only cell line where detectable levels of PRL-3 protein have been reported (Geiger et al., 2012; Wang et al., 2010) and that can be cultured to grow in three dimensions and to form lumen-containing structures (do Amaral et al., 2011; Lee et al., 2007).