Moreover, CXCR4-specific siRNAs (siCXCR4 #1 and #2) significantly repressed CXCR4 expression levels compared with siControl (Figures 3M, O) and impaired the viabilities of RCC-PDC spheroid cultures (Figures 3N, P). The gene discussed is CXCR4; the disease is renal cell carcinoma.