PPM1D and non-small cell lung carcinoma: Based on the ability of WIP1 to dephosphorylate and inactivate p38, and the correlations among increased WIP1 expression, reduced p-p38 levels, and increased CSC marker ALDH1 expression in NSCLC, we investigated the possibility that WIP1 promotes stemness-related protein expression and CSC properties by inhibiting p38.