C1RL and cancer: For each cancer ceRNA network, we found that the expression level of a number of lncRNAs was specific to each cancer: SNHG12, AC005154.1, CCDC18-AS1, and SNHG7 were specific for LIHC; SNHG3, TMEM161B-AS1, and AC093010.3 were specific for ESCA; SNHG15, AC015813.1, and CCDC183-AS1 were specific for READ; C1RL-AS1, LINC00707, and LINC00958 were specific for HNSC; OR2A1-AS1 and MALAT1 were specific for COAD (Figure 1 and Supplementary Table S2).