PTGDR and gastric cancer: Within the abovementioned coexpression network, one lncRNA, TOPORS‐AS1, whose functions were predicted as cellular respiration, oxidation–reduction process, translational termination and so on (Figure 2), and the associated NDUFB6, which is located in the same genomic regions with opposite transcript direction, were both verified to be downregulated in gastric cancer samples by RT‐PCR (Figure 4).