The functional relevance of these autocrine and paracrine feed-forward loops, originally proposed in multiple myeloma [107] and comprising the IL6/gp130/Stat3 cascade, has recently been extended to solid tumours, including lung adenocarcinoma [20], prostate cancer [108], ovarian carcinoma [109] and Ras-transformed cancer cells [110]. This evidence concerns the gene STAT3 and cancer.