To explore the role of TMPRSS4 in triple negative breast cancer cells radiosensitivty, TMPRSS4 was down-regulated by transfecting TMPRSS4 silenced lentivirus vector in MDA-MB-468 breast cancer cell line which has been reported to overexpress TMPRSS4 (Cheng et al.,2013; Li et al.,2017; Assani et al., 2019). Here, TMPRSS4 is linked to breast cancer.