SMAD7 and cancer: Our previous study found that EBV-miR-BART7-3p activated the PI3K/AKT signaling pathway to promote metastasis and EMT of NPC cells by targeting PTEN (Cai et al., 2015a), suggesting PTEN may also induce cancer stem cell formation in NPC as reported by other articles (Matsuda et al., 2018), so SMAD7 may not be the unique target of EBV-miR-BART7-3p in NPC.