IL6 and neoplasm: In in vitro organotypic co-cultures with human fibroblasts and a human skin carcinogenesis model (HaCaT-ras A-5RT1 cell line), IL-6 was found to activate fibroblasts and encourage progression to the tumour-associated fibroblast phenotype, activating expression of metalloproteinase-2, thus promoting the invasive capabilities [158].