CTLA4 and melanoma: In the last 2 decades, immunotherapy including programmed death-1 (PD-1), cytotoxic T lymphocyte associated antigen 4 (CTLA4), and programmed death ligand-1 (PD-L1) inhibitors, demonstrated major breakthroughs and became the major therapeutic approach in solid tumors, such as non-small-cell lung carcinoma (NSCLC) and malignant melanoma [3, 4].