CCL21 and nonpapillary renal cell carcinoma: Univariate subgroup analyses showed that CCL21 expression was a risk factor in ccRCC patients (P = 0.019), patients treated with sorafenib (P = 0.012), patients with one metastatic site (P = 0.044) and patients with no lymph node involvement (P = 0.019) (Table S2).