SERPINE1 and gastric cancer: Given that the NKX2‐1‐AS1/miR145‐5p/SERPINE1 was the only ceRNA regulatory axis that revealed a negative association with OS at both its lncRNA and mRNA levels and that miR‐145‐5p was expressed at a low level in cancer tissues, our data suggested that the NKX2‐1‐AS1/miR‐145‐5p/SERPINE1 axis might have a potential role in predicting the prognosis of GC patients.