In contrast, P38γ and P38δ activation may suppress CSCs development in non-small-cell lung cancer (NSCLC) through promotion of the ubiquitin-mediated degradation of SOX2, OCT4, NANOG, KLF4 and MYC transcription factors that normally contribute to the acquisition of cancer stem cell characteristics [211]. This evidence concerns the gene KLF4 and non-small cell lung carcinoma.