In further studies performed in vitro, benchmarking of STA-8666 to irinotecan in NSCLC models showed similar or greater efficacy in inhibiting ERK1/2 activation, and a stronger phenotype of induction of checkpoints associated with DNA damage, and confirmed lack of an effect on epithelial or mesenchymal status. This evidence concerns the gene MAPK3 and non-small cell lung carcinoma.