Thus, we explored whether XIST is involved in the chemoresistance of NSCLC cells to DDP We found that XIST was overexpressed in DDP-resistant A549 (A549/DDP) and H1299 (H1299/DDP) cells, compared to their DPP-naïve parent cells (Figure 3A). The gene discussed is XIST; the disease is non-small cell lung carcinoma.