CTLA4 and clear cell renal carcinoma: We present a literature review and a rare clinical case from our clinical practice, in which a patient with metastatic clear cell renal carcinoma was treated with a single dose of dual checkpoint blockade (cytotoxic T-lymphocyte-4 (CTLA-4) and programmed death-1 (PD-1)) and simultaneously diagnosed with colitis, hepatitis, and nephritis.