USP39 and clear cell renal carcinoma: Ubiquitin-specific protease 39 (USP39), a deubiquitination enzyme [78], enhances vascular EC tube formation in clear cell renal cell carcinoma (RCC) by downregulating VEGFA165b, an endogenous splice isoform that inhibits VEGFA165 [79], though without significantly affecting overall VEGFA expression [56], which promotes the proliferation of the RCC.