PCAT18 and rectum adenocarcinoma: By analyzing the GEPIA database, we found that the expression levels of MIR100HG, SERTAD4-AS1, and PCAT18 were significantly downregulated; however, KRTAP5-AS1 was upregulated in both colon adenocarcinoma (COAD) and rectum adenocarcinoma (READ) samples compared with that in normal tissues (Figure 6).