IL6 and cancer: Among the 50 cancer hallmark gene sets of eight functional categories16, only seven gene signatures in the immune category (allograft rejection, coagulation, complement, interferon alpha response, interferon gamma response, IL-6/JAK/STAT3 signaling, and inflammatory response) were consistently distinguish between the two groups when mapped to PC2 (Fig. 1c) (mean GSVA score = 1.16).