ELFN1 and rectum adenocarcinoma: ELFN1-AS1 and AC012363.4 were among the identified functional ORF-encoding lncRNA genes with the most cancer-specific expression in COAD and/or rectum adenocarcinoma (READ), that is, they not only showed much higher expression in COAD and/or READ than in the corresponding normal tissues, but they also showed a relatively low expression across different normal tissues (Fig. 1d and Extended Data Fig. 1g).