FN1 and renal cell carcinoma: To better assess RCC-associated stromal progression, here we investigate additional stromal markers which were simultaneously assessed in vivo using the same original samples: Palladin, an early myofibroblast differentiation marker localized to fibroblastic stress fibers [12]; EDA, a spliced form of fibronectin, upregulated during renal tumor stromal activation [3]; and uPARAP/Endo180, also upregulated in the activated tumor microenvironment [13] and tentatively associated to ECM (e.g., collagen I) degradation [14], facilitating tumor invasion and metastasis [15].