MUC5AC and lung cancer: Notable takeaways from these two studies on NPC-1C-reactive in the context of PDA are: (a) it is expressed exclusively in pancreatic and colon cancer tissues; (b) it is different from native MUC5AC expressed in lung cancers and normal tissues identified by 45M1; (c) it is detected in the serum of pancreatic cancer patients; (d) it is immunogenic.