ESR1 and breast cancer: It is also discussed that autophagy is a key mechanism of cell survival during anti-estrogen treatment and progression of drug resistance in breast cancer cells.45, 46 We previously showed that ERα expression mediates increased resistance of neuroblastoma cells to oxidative stress.21 To further investigate whether ERα-induced autophagy contributes to increased cell viability after stress induction we co-treated the cell lines with BafA1 to inhibit the late phase of autophagy (Figures 5a–d).