Subsequently, 13 lncRNAs, whose levels were different between CRC patients and HCs, were used for a bidirectional stepwise logistic regression model, and the diagnostic score was calculated according to the following formula: DXscore = −0.384 – 0.123 · PHB‐AS + 0.0789 · CSRP1‐AS1 + 0.108 · SOS1‐IT1 + 0.0658 · PDPK1‐AS + 0.182 · RP11‐110G2–0.165 · SLC7A9‐AS – 0.0538 · ENSG00000261765. The gene discussed is PTGDR; the disease is colorectal carcinoma.