We have previously identified miRNA 519a-3p (miR-519a-3p) to be upregulated in tamoxifen-resistant breast cancer cells.28, 29 MiR-519a-3p targets several tumor suppressor genes, thereby increasing cell viability and cell cycle progression.29 In the present study, we analyzed the effects that miR-519a-3p has in TRAIL and Fas ligand (FasL-)-mediated induction of apoptosis. The gene discussed is FASLG; the disease is breast cancer.