TM9SF4 and breast cancer: Findings demonstrated that shRNA-mediated TM9SF4 silencing increases ER stress by causing misfolded protein accumulation in adriamycin-resistant MCF-7 and gemcitabine-resistant MDA-MB-231 breast tumorscompared to wild-type cells and may result in apoptotic and necrotic cell death activation.Based on the findings, it emphasizes that TM9SF4 may be a possible target therapy strategy to overcome the chemoresistance barrier in breast cancer treatment (Zhu et al., 2019).