Caspase 3/7 Glo assay: Cells were incubated with the respective inhibitors or control for 48 h and later enzymatic activity of caspase 3/7 was examined (SPARK10M, Tecan) by using caspase 3/7 dependent Glo assay (absorbance at 405 nm), following manufacturer's instructions (Promega). Zebrafish: Zebrafish wild-type TE strain were maintained according to standard protocols and handled in accordance with European Union animal protection directive 2010/63/EU and the local government (Tierschutzgesetz §11, Abs. 1, Nr. 1, husbandry permit 35/9185.46/Uni TÜ). All experiments described in this study were conducted on embryos younger than 5 days post-fertilization (dpf) -prior to the legal onset of animal life.