PTGS2 and non-small cell lung carcinoma: As shown in Figure 5D, pretreatment with celecoxib (CB) alone also inhibited cell viability, whereas a combined treatment with melatonin and berberine did not significantly alter cell viability inhibition mediated by the COX-2-selective inhibitor, indicating that COX-2 signaling is also an important target for melatonin in NSCLC cells.