HSPB1 and nonpapillary renal cell carcinoma: Using proteomic analysis, 55 proteins were identified to be significantly dysregulated in ccRCC compared to normal kidney tissueHeat shock protein beta-1 (HSPB1/Hsp27) was confirmed in two independent sets of patients by western blot and immunohistochemistryHsp27 was elevated in the urine and serum from RCC patientsHigher tumor grades (grade III-IV) were associated with higher Hsp27 expression in patient serum (p = 0.013)