For immunohistochemistry, slides were deparaffinized and rehydrated, blocked in sheep serum for 30 min, and then incubated with anti-Beclin 1 (ab55878, Abcam), anti-ATG6L1 (GTX129093, GeneTex, Irvine, CA, USA), anti-SQSTM1 (PM045B, MBL, Woburn, MA, USA) or anti-γH2AX (#9718, Cell Signaling Technologies) overnight at 4°C. The slides were mounted and the images were captured and analyzed by a fluorescence microscope.