Analysis using western blotting indicated that in NPC cells treated with gemcitabine and APG-1252-M1 in combination, increased cleavage of PARP, caspase-3, and caspase-9 occurred compared with that caused by either treatment alone (P < 0.05; Fig. 2e–g; Supplementary Fig. 2c, d). This evidence concerns the gene CASP9 and nasopharyngeal carcinoma.