(C) Representative electron micrographs of H1299 neo and HA‐BCL‐2b5 cells treated with either LUC or NAF‐1 siRNA, with or without subsequent starvation. Scale bar represents 10 μm. Cell lysates were analysed by immunoblot. All lanes are derived from the same gel and of the same exposure. Thin white line indicates where lanes have been removed. Autophagy levels observed by electron microscopy (C) were quantified and expressed as either the percentage of cells containing autophagic vacuoles (D) or the number of autophagosomes per cell (E). A minimum of 100 cells per sample were counted; results represent the average±s.e.m. 