In this study, we analyzed four published datasets and one newly generated dataset with RNAseq data available for pre- and on-treatment tumor specimens derived from patients with metastatic melanoma who were treated with anti-PD-1/PD-L1 monotherapy, anti-PD-1/PD-L1 monotherapy with prior anti-CTLA-4 monotherapy, or the combination of anti-PD-1 plus anti-CTLA-4 therapies (Fig. 1a, b). The gene discussed is CTLA4; the disease is metastatic melanoma.