CTLA4 and metastatic neoplasm: Among the 23 variables included in the RSF model, five were selected: ICI treatment type (anti-PD-1 mono vs anti-CTLA4 combo), ECOG PS at baseline (0 vs >0), NLR (modeled as binary variable ≤3 vs >3, using a literature cut-off14), PLT count (continuous linear term) and prior lines of treatment for metastatic disease.