(a) U937 cells were transfected with siRNA specific to FIS1, DRP1 or IRGM (or control oligonucleotides) as indicated, followed by plasmid encoding GFP-LC3. Autophagy was induced by treatment with hIFN-γ. GFP-LC3 puncta in cells were imaged by confocal microscopy. Scale bars, 5 μm. (b) LC3 puncta per cell were quantified from cells treated as in a. 