CXCL8 and neoplasm: This patient had a focus of sarcomatoid dedifferentiation in his primary tumor at the time of cytoreductive nephrectomy, and indeed the 3 patients who had sarcomatoid or rhabdoid differentiation (patients 7, 20, 29) had overall higher than median levels of the 7 cytokines that were elevated in the index patient, with the exception of TNF-α and IL-8 for patient 29 (Figure 4C).