CTLA4 and melanoma: On performing functional annotations by IPA and comparative analysis for the transcriptomic signature of both study entities, we found that three pathways, namely the “Pathogen induced cytokine storm”, “Macrophage classical activation”, and “FAK signaling”, were activated in both melanoma and HCV infection, in which two key players, IL6 and CTLA4, were essentially activated and had significant implications in the curated HCV-melanoma network.