CXCL8 and renal cell carcinoma: Later it was shown that other cell types could produce IL-8 and that it is upregulated in several types of malignancies, contributing to processes such as proliferation, angiogenesis, invasiveness, and metastasis.22 IL-8 has recently been shown to be upregulated and correlated to metastasis and epithelial–mesenchymal transition also in a RCC cell line and RCC tissue, probably of clear cell origin.23 However, to our knowledge, our study is the first to identify IL-8 as a factor being produced by pRCC cells.