PPM1D and non-small cell lung carcinoma: We previously demonstrated that reduced p-p38 levels correlated with increased SOX2 levels in NSCLC tissues, and that activated p38 suppressed CSC properties in NSCLC cell lines.25 To investigate whether the WIP1-mediated suppression of p38 activity contributes to CSC properties, we determined the relationship between WIP1 expression and levels of ALDH1, which is a well-established CSC marker in NSCLC,33 by analyzing data from The Cancer Genome Atlas (TCGA) database.