(a) Fluorescence microscopy of Hoechst-counterstained HeLa cells transiently transfected with LC3-GFP subjected to 100 μM spermidine for 6 h. Representative pictures are shown. (b) Percentage of adherent cells exhibiting a clear LC3-GFP relocalization into cytoplasmic vacuoles. Numbers were determined using micrographs of Hoechst-counterstained HeLa cells as representatively shown in a. Data represent means ± s.d. (n = 3). 