Given the above observations that DR4 reduction induced by osimertinib or other EGFR-TKIs is accompanied with increased PARP cleavage and tumor growth as demonstrated in vitro and in vivo, we used DR4 shRNAs to transiently knock down DR4 expression in PC-9 cells followed by treatment with osimertinib and then detected apoptosis. Here, EGFR is linked to neoplasm.