UBB and nonpapillary renal cell carcinoma: Moreover, it was evident that the Type 3 group exhibited a notably higher proportion of TKI-resistant patients and TKI-resistant patient-derived xenograft (PDX) models than the other two groups, indicating that ccRCC patients with reduced UBB levels coinciding with elevated VEGFA levels illustrated a propensity for TKI resistance (Fig. 6B).