#CMTCN is a freely available web tool that provides a comprehensive and intensive analysis of combinatorial regulatory interactions between transcription factors, microRNAs, and target genes.For each type of cancer, CMTCN identifies four types of 3-nodes TF-miRNA co-regulatory motifs (three FFLs and one co-regulation motif) consisting of a TF, a miRNA and their co-targeted gene. CMTCN can construct and depict cancer-specific co-regulatory networks in various tumor types, and meanwhile, it uncovers miRNA and TF co-regulatory relationships. On top of all that, CMTCN screens out important nodes in the co-regulatory network based on network topology analysis and provides genes/TFs/miRNAs enrichment according to different annotated datasets.