PIWIL1 and non-small cell lung carcinoma: treated two non‐small‐cell lung carcinoma (NSCLC) cell lines (A549, H23 cells) using the demethylating agent named 5‐aza‐2′‐deoxycytidine (5‐AzadC) and observed a dose‐dependent increase in the PIWIL1 expression levels 26.