CASP9 and lung cancer: Given our previous finding that procaspase-9 is inhibited in NSCLC H460 cells [15], we started our investigation by examining the expression levels of the main apoptosome components Apaf-1 and caspase-9, in a broader panel of lung cancer cell lines, including the NSCLC cell lines H460, SW1573, A549 and H322, and the SCLC cell lines GLC4, N417 and H187 by Western blotting.