For this, we stably knocked down HSP27 in A2780CIS and PEO4 cells (the HSP27 knockdown efficiency of ovarian cancer cell lines tested was confirmed in Figures S3A–C and S13A–C), treated them with cisplatin, and measured mitochondrial and cellular ROS levels with MitoSOX and CellROX dyes, respectively. Here, HSPB1 is linked to ovarian cancer.