MUC1 and lung cancer: In addition, highly expressed mucin 1 (MUC1) can activate the nuclear factor-k-gene binding (NF-κB)/ZEB1/PD-L1 signaling pathway, leading to poor prognosis of nonsmall cell lung cancer (NSCLC), while blocking therapy targeting PD-1/PD-L1 can significantly improve NSCLC treatment, suggesting that PD-1/PD-L1 co-expression plays a carcinogenic role in NSCLC [22].