IL6 and pachyonychia congenita: Next to the possible paracrine, and EMT-affecting, signaling from cells within or around the bone metastatic niche to PC cells, compressed PC cells themselves also show altered gene expression of TGF-β1, PTHrP, IL6 and GDF15 as well as altered IL6 protein secretion in this study, which have the potential to affect their EMT-phenotype in an autocrine fashion, as well as altering the behavior of cells in the metastatic niche such as osteocytes and marrow stromal cells via paracrine signaling.