As a cyclin-dependent kinase, CDK8 not only controls the cell cycle through interactions with other proteins but also phosphorylates transcription factors and participates in transcription processes, thus controlling a number of signaling pathways linked to tumor formation, including transcriptional regulators, signaling systems, modifications in the tumor cycle, DNA damage repair, energy metabolism, invasion, and metastasis. This evidence concerns the gene CDK8 and neoplasm.