qRT-PCR was performed to detect the expression of PCAT19 in cancer tissues and ANT collected from 74 LC patients, and the results exhibited that PCAT19 was conspicuously downregulated in tissues of LC patients (P < 0.001, Figure 2(a)), with the mean PCAT19 expression level being 4 ± 1.2 (Figure 2(B)). This evidence concerns the gene PCAT19 and cancer.