FOXO3 and lung cancer: However, a previous study suggested the distinct roles of RRM2B in tumor progression: on one hand, its amplification was related to worse outcomes in breast cancers (Chae et al., 2016; Iqbal et al., 2021); on the other hand, in vitro analysis found its overexpression could inhibit the proliferation of lung cancer cells by the regulation work of FOXO3 (Cho et al., 2014).