FOXP3 and neoplasm: On the one hand, FOXP3 can act as a tumor suppressor in breast cancer (Zuo et al., 2007), ovarian cancer (Zhang and Sun, 2010), colon cancer (Li et al., 2013), and gastric cancer (Ma et al., 2013), but it can act as an oncogene in non-small cell lung cancer (Yang et al., 2017), lung adenocarcinoma (Li et al., 2016), and thyroid cancer (Chu et al., 2015).