g-i, Atg5-/- MEFs were transfected with the indicated siRNAs for 24 h and treated with etoposide. Induction of macroautophagy was assessed by Lamp2 IF (g) and by EM (h), and the number of isolation membranes was calculated (i). In g, error bars indicate s.d. (n = 4). In h and i, red and blue lines indicate means and s.e.m., respectively; n = 35 cells each. 