Knockdown of ATG5 sensitizes chemoresistant 5637 cells to (−)-gossypol. Quantification of total cell death and early apoptosis by flow cytometry (Annexin V/PI). Empty vector–transfected 5637, 5637rGEMCI20, 5637rCDDP1000 cells (Ø-vec) and 5637, 5637rGEMCI20, 5637rCDDP1000 ATG5-KD cells were treated with 10 μM of Mcl-1 sparing Bcl-2 inhibitor ABT-737 and 15 μM of pan Bcl-2 inhibitor (−)-gossypol for 48 h. *, P < 0.05 compared with the control. #, P > 0.05 compared with Ø-vec with the same respective treatment. n.s., not significant (A-C). Representative data from the experiment B and C in 5637rGEMCI20 Ø-vec, 5637rGEMCI20 ATG5-KD and 5637rCDDP1000 Ø-vec, 5637rCDDP1000 ATG5-KD shown in D exhibited as FACS dot plot profiles.